X5 4.4 - Sludge in engine and oil filter housing... help!
 

So I changed the oil for the very first time on the 03 4.4 I just bought two weeks ago and to my surprise.... WOW: wow: talk about sludge everywhere in the in the engine and filter housing! I was disgusted. ;puke;

How could someone be so careless to leave their oil in the car so long that it turns into sludge!?! There was rock like black crystals in an oil filter that said it was made in India.

Needless to say, I cleaned whatever I could in the oil filter housing and drained ALL of the nasty burnt oil from the car and replaced with OEM Oil Filter and Almost 9 Qts of Mobile 1 5w/30.

The car has 100k on it and the engine runs fine as if you could not tell it has that entire gunk built up inside of it.

My Question....

What can I do to safely remove all the build up from inside the engine components? I am planning on dumping this oil in about 2,000 miles and it's a waste since it's Mobile 1 and cost almost $70. Has anyone ever had a similar situation? If so, how did you deal with it?

Any thoughts would be appreciated!:beerchug::thumbup:

Sheesh.... now you have me worried!

as for your poll, my service advisor told me that BMW recently redefined lifetime as 100k, so according to BMW you should change the trans oil. But on the other hand, there are certain particles in there that you might not want to lose

Transmission Oil Change
 

I have an independent mechanic that I took it to who knows these cars in and out. I asked him the same question and he said change it, but there is always a risk. In his opinion though, the risk is greater if you drive and not change the oil at all.

From what I understand, there is only one type of Transmission oil that can be used on this car and it's not available to the public.

The mechaic wants $500 to do the oil change - $30/qt x 10 qts + 200 labor.

Sounds a bit steep but he justifies it with 500 for an oil change or 5,000 for a transmission.

Do you know if BMW sells the oil to the public? Or is it available anywhere else? Thanks.

I got the impression he was talking about the engine oil and not the transmission fluid.

I'd recommend you flush it at the 2,000 mile mark as planned and then not worry about it.

I think you are on the right track. I would do a couple short interval oil changes when the oil is nice and hot. I wouldn't put in any additives or anything else like that.

As far as the trans is concerned. I don't think any fluid is "lifetime fill". However, the problem is that there are possible risks to changing the fluid out for the first time at a higher mileage (say 100,000 miles).

I am no professional, just my $0.02.

What are the risks?

How come you made the poll so way off topic? lol

Read this thread;

http://www.xoutpost.com/bmw-sav-foru...intenance.html

Especially the first post by JCL. He knows his stuff.

Your post is terribly confusing. First you post a survey question about TRANSMISSION FLUID (NOT OIL) and then you talk about ENGINE OIL.

You should mention where you bought your car, the # of miles, how was it maintained, etc.

Frankly I'm amazed that someone smart enough to find their way onto Xoutpost didn't get a 7 year old car looked over by a professional mechanic prior to purchase, but that's a side point.

$70 for oil, better get used to it. I'd change it every 1,000 miles at this point given what you wrote.

And as far as automatic transmission FLUID is concerned, yes you can buy all the fluids readily. It has been discussed and written up in this board and you can go to your local BMW dealer and get part numbers etc if you don't want to do any searching. As far as whether or not you should change it, you'll get as many opinions on the matter as there are X5's on the road.

His post was a good read but I didn't see anything which demonstrated any risk. The only risk related comment he made was:

"That is what can disturb sediment that wasn't otherwise hurting anything, IMO."

However he earlier stated such a risk was:

"My lack of support for changing the fluid is not because "BMW said" but rather because I see little benefit to changing it, and a small but real risk. The risk of damage is slight, but it exists."

I do see his point of:

"At the same time, I think that the transmission is likely to fail from non-fluid related causes prior to the fluid degrading to the point that it causes a transmission failure itself."

But I'd rather minimize the likelyhood of such failure by ensuring the fluid is in good condition.

That is the thing though, if you change it from early on, I think it is better. If you wait until 100k+ and change it for the first time, you are running the risk of dislodging sediment (whatever else) and that is something that can potentially cause issues on higher mileage transmissions. Not saying it will happen, but can. There are enough threads on this topic floating around to keep you busy for days on end.

There is the possibility of dislodging sediment but even if that were the case I have seen no evidence to support that dislodged sediment correlates to transmission failure. So while the risk is there I think a transmission failure resulting from it is so rare as to make it a non-issue.

I found this post from JCL in one of the numerous trans fluid threads...

On higher mileage transmissions it isn't the metal shavings you have to worry about, although there could be some. If you have metal shavings, it doesn't really matter if you change the fluid or not as the transmission is likely on its way out. What wears inside a transmission are the clutch packs (multi-disk wet clutches) and the bands; both are surfaced with a non-metallic friction material that wears over time. That material is what can clog a valve body. It sits there undisturbed but can be moved by a fluid change. Clean fluid doesn't dissolve it, but draining the fluid and then starting it up and repressurizing the clutch packs can move it around. It may not happen, but in any case that is the theory behind the risks of changing fluid on high mileage transmissions.

I am going to jump off the JCL train now. :rofl: I am not saying this is going to happen, but I guess I wouldn't call it a non-issue either.

My largest concern is with moving sediment around upon repressurizing clutch packs, solenoids, etc. It is a classic failure mode for transmissions that otherwise work fine, have no apparent problems, get a fluid change and then fail soon after. If you don't think it is a risk, then you should change the fluid. We aren't talking absolutes here, whereby every fluid change causes a subsequent failure, just a risk profile, whereby there are many failures that can be attributed to fluid changes.

The other risk is that the fluid has changed viscosity over time, and when you put new (thinner) fluid in, it doesn't work as well due to being thinner. The transmission adapts to different fluid characteristics over time.

FSETH actually saved me a lot of typing, thanks bud!

Thanks. That was a great post. I am leaning towards chaning the fluid. I'm thinking it won't go bad, and if it does, then it was going to very soon because the oil had already broken down causing mechanical problems. I am thinking about sending the Tranny Oil to be checked out by a lab prior to changing the oil though. This way I can get an analysis to see if the oil inside is any good or not, making my decision a bit easier.
:bustingup

A few years back some dealers were offering an engine oil flush of some sort where they would I think reverse flush the engine and emulsify the oil and sludge, etc. A few master techs suggested it wasn't a bad idea on a high mileage car. Never did it myself, but maybe that's something you should consider.

I previously acknowledged the possibility of disloding sediment. However my personal opinion, and it appears it is shared by JCL, is the possibility of it happening is very low. Furthermore should sediment be dislodged I have seen no evidence it will result in a transmission failure. So the chances of dislodging sediment are very low and the chances of dislodged sediment resulting in a transmission failure are very low.

This is just a restatement of the post FSETH linked to. There you said you felt the chances of dislodging sediment are slight. I agree with this. There is a possibility but I don't see it being very high. Nor do I see any evidence the dislodged sediment, in the slight case it occurs, results in transmission failure.

I am assuming you're replacing the fluid with the recommended fluid. Which makes this point moot.

It is not just a restatement. The chances of a fluid change causing a transmission to fail are slight, but still very real. You have to weigh that against the benefits of clean fluid. What makes you think that clean fluid will make the transmission last longer? There is no data to support that point of view. I say the chances are slight, because posters regularly change their fluid, don't have a failure, and then conclude that this is proof it was a good idea. It isn't proof, it is simply proof that they dodged the bullet, and good for them in that case. I won't change my own transmission fluid because I see no reason to. The transmission failures we have seen haven't been caused by worn out fluid.

Talk to anyone who has worked in a transmission shop, and they will confirm that they regularly get overhauls caused by unneeded fluid changes. Doesn't happen with every fluid change, but it is a very common failure mode. Sludge that wasn't hurting anything gets flushed into the valve body when you refill it and restart it, on the initial pressurization; that sludge then clogs an orfice, and causes an actuator or sensor to fail.

If you are replacing the fluid, I assume you are using the correct fluid specification. That doesn't make my point moot, however, as fluid changes viscosity over time. That is known to the engineers, and the transmission adapts to the fluid as it ages. There are feedback sensors on things like clutch delays, etc. When you put thinner (correct, but still thinner) fluid in, you can get failures. Again, transmission mechanics are familiar with this. It has been discussed on this site by BMW techs.

All of this said, do whatever makes you happy. If you think you want to change the fluid, just change it. If it causes a transmission failure, you can always tell yourself that it was going to happen anyway, and that you didn't initiate it. If it doesn't fail, you win as well. :thumbup:

We're in agreement there is a slight risk accumulated sediment can be dislodged. However I have seen no evidence to suggest dislodged sediment results in significant numbers of transmission failures. Therefore, in the absense of data to the contrary, the risk is so minimal as to make it a non-issue.

As to the benefit lubricants breakdown and become dirty over time and their ability to provide the protection they once did is reduced. Thus increasing wear on the components.

Given this I believe replacing the fluid has benefit that far exceeds the risk.


I spoke with my mechanic about this and he recommends replacing the transmission fluid at regular intervals. As a matter of fact I had never heard of transmission failures resulting from fluid changes until I started reading BMW forums. I have seen no data to support changing the oil correlates into any significant number of transmission failures. Your reasoning makes sense but I think it is applicable in only a small number of cases.

If you use the correct fluid why would the viscosity be relevent?

This is a specious conclusion. If, after changing the fluid, the transmission fails how do you know it wasn't about to fail regardless? I think we're all aware of people who, in a desperate attempt to avoid a rebuild/replacement a transmission, hope changing the fluid will fix a symptom of a failure. Conversely if the transmission doesn't fail how do we know it was luck and not preventative maintenance?

Have you ever worked overhauling transmissions? I suspect not. It isn't a non issue to those of us who have, but it may be to you. That's cool.

No argument. Only issue is, is it relevant? Are X5 transmissions failing due to lubricant quality? Not according to the posting history on this board and others. Sensor failures, actuator failures, programming failures, are all unrelated to fluid quality. They are at the root of many early transmission failures. Changing the fluid won't improve your odds.

Then you should change your transmission fluid. You are the only one who will live with the consequences, so just do it.

My reasoning is based on working in a shop. I can't tell you what to do, just that I won't change my own transmission fluid. I do believe in preventative maintenance. I just believe that in the case of the X5 transmission, the risks outweigh the benefits.

I wasn't referring to those cases. I was referring to the multiple cases where a transmission worked fine, up until soon after it had the transmission fluid changed. It happens too often. Technicians in transmission repair shops know about it. You can discount it if you like. It is the reason that those of us who have rebuilt transmissions make judgement calls on whether to change the fluid in this case. I think there is a small chance of a fluid change causing a failure, overall. I think there is even less likelihood of degraded fluid causing a transmission to fail. Look on this board for all the posts that start off "FML, my transmission failed, and wouldn't you know it, I even changed the fluid recently". If you choose to take the chance, no problem, rest easy in the knowledge that your transmission probably won't fail due to a fluid change anyway. Just don't expect it to last longer, that is my point.

No I have not. Nor do I work rebuilding engines. That doesn't mean I can't make an informed decision about whether I should change the engine oil. I've spoke with my mechanic about this prior to having the transmission fluid in my X5 changed. He's well aware of this ubran legend and doesn't buy into it. That, combined with a complete lack of supporting data, is enough for me.

They could be. But I'm not arguing pro transmission fluid replacement (though I think it's a good idea). I'm arguing I have seen no evidence to support changing it increases the likelyhood of failure. And so far you've provided no such data either. Just anecdotes stating you've seen transmissions fail after the fluid was changed. It is your theory the transmission failed because of the fluid change but you cannot offer anything other than a theory. What is surprising is you continue to say there's a slight chance it could happen. Of which I agree. However slight does not make a correlation.

Already done.

That's fine. I'm not here to convince you to change your fluid. You feel there's no benefit. I disagree. Fluids break down. They get dirty. Replacing them is good maintenance, IMO.

However I did ask what the risks are to changing the fluid. So far the only risk I've received is that there's a slight possibility doing so could dislodge some sediment. Which I'm sure there are some examples. Not enough to offset the benefit of changing it...IMO.



But you can't say the transmission failure was due to changing the fluid (unlikely, IMO) or some other issue of which a transmission fluid change was a last ditch effort to avoid a costly transmission rebuild/replacement.

You're also forgetting that a transmission shop isn't going to see all the transmissions where a fluid change was performed and no failure resulted. So your sample is limited almost exclusively to those transmission which failed.

We did a poll on here on that very subject of failing transmissions after fluid change. Mind you it was far from statistically accurate but I was very surprised to see that no one had reported a failure after fluid change and 10K mles after. I was really surprised and the more I asked the more of "urban legend" it seemed to become. Certainly out of proportion to reality.

I believe I can, if my shop did the only maintenance to the vehicles in question, and knew the vehicle history. I have already discounted the cases where changing the fluid was a last ditch effort to avoid transmission repair.

The shop in question (in my case) was a general repair shop, that did not do transmission work exclusively. We overhauled some tranmissions, and worked with specialist shops that could do it cheaper in other cases. There is a clear correlation with increased failure rates after fluid changes, it wasn't just our shop. That said, clean fluid is a good thing. It just didn't always make transmissions last longer (which was the primary reason that owners wanted to change transmission fluid, to increase the life of their transmissions)

You are correct that it had no statistical significance. What I found surprising was that some members who had failures after changing the fluid, and had posted about them, didn't respond to the poll.

[QUOTE=ArNarX5;730663]So I changed the oil for the very first time on the 03 4.4 I just bought two weeks ago and to my surprise.... WOW: wow: talk about sludge everywhere in the in the engine and filter housing! I was disgusted. ;puke; <snip>

I recommend you get an oil analysis done when you change the oil the next time. Blackstone Labs will send you a free kit and analyze your oil for $22.50. There are a bunch of guys over on the m3forum.net who have used this service and the info they get back is very useful. Here is a link to one of their analysis threads.

500 for a tranny fliud change?!!! HAHAHAHA its a few bolts and filter anyone could do it

I wouldn't say that. In fact, that statement is stupid at best and shows your ignorance. The proper fluid for that transmission alone will cost over $300. There is a pretty detailed procedure of what you should do before, during and after refill. The instructions are certainly not trivial.

I suspect your shop saw only a small number of BMWs making the sample size too small to be of value.

Would you mind posting the supporting data?

I don't know if it does or not. We replace every other fluid in our vehicles in order to increase service life so I fail to see why the transmission fluid should be any different.

A very small number. But that is irrelevant, at least until BMW start to make their own automatic transmissions.

Yes.

That is getting to the essence of the debate. Think of the risk of an fluid-change induced transmision failure as x. Think of the benefits of clean fluid making the transmission last longer, and that being relevant to the life of the vehicle, as y. It is simply a case of whether the risk of x is greater than the benefit of y. X is greater than 0, it isn't 0. It isn`t an urban legend as you described it above. Y used to be quite large, which is why we used to change transmission fluid every 30,000 miles or so. Y isn't so large today, because we now have factory installed transmission coolers with thermostats, we have lock-up torque converters that keep the fluid temperature down, we have programmed shifts that reduce clutch slip, and we have feedback loops in the actuators so the transmission can compensate for fluid viscosity change over time. Presumably clean fluid could make it last longer, but there are posters here who are over 200,000 miles on the original transmission fluid. Many transmission will last longer than the chassis, simply because it will become too expensive to do software updates. These are not cars that are going to be cheap to own as they age, and that is going to greatly reduce the number of them on the road. At the same time, there are lots of early hour transmission failures (lots is relative, let's just say more than we would like to see) and they do not appear to be related to oil quality, but rather random failures of software, sensors, etc. Not things that would fail less frequently if the oil was cleaner. What happens is that because of those early hour failures, owners consider changing the fluid to improve their odds. That is faulty logic.

It is simply a judgement call that each owner has to make. There is no right and wrong answer, there are just risks. I think it is worth pointing out that not changing the fluid is not some nonsense dreamed up by a marketing organization at BMW, there is a technical reason and in many cases it makes sense. If owners are going to change the fluid, then I think that they have to change the filter at the same time, they probably should change it two or three times in short order to get the bulk of the old oil out (since there is no torque converter drain), they should use factory spec oil and not try the roulette game of various aftermarket oils that may or may not work, and they should refill it according to the BMW procedure that involves taking fluid temperature readings during setting the level.

Possible Sludge Remedy
 

Hello ArNarX5.

I know oil flushing is not a popular remedy on this website. In two of my previous cars I used BG products for preventive maintenance.

Here are a couple of links for your review:

MotorWeek: Auto Basics: Goss' Garage

BG Products, Inc.

I see you are in Burbank. I have my X5 serviced at Center BMW. They do not have the BG service. Casa Motors in Sherman Oaks does. I had the BG oil flush done on two of my SAABs at 30k as discussed in the MotorWeek article. I did this based on my dad's recommendation, not MotorWeek. I just saw this MotorWeek episode in 2009.

I have no direct expertise in car maintenance. My dad was the mechanic, a retiree from LA City. He retired 20 years ago, so I know he was trained old-school. Funny thing, he worked on all his cars, up until his death last year at 84. The only work he would not do was related to air conditioning. Sorry for the digression.

Given you've only seen a small number I will restate that your sample size is too small to be of relevence.

I don't see replacing fluids as faulty logic. We do it for engine oil so why shouldn't we do it for transmissions?

I do agree that fluid life has increased considerably over the years. That doesn't make it lifetime fluid.

As for X I have seen no data, and you refuse to provide your own, that supports it is significant. Is there a risk? Most certainly. And by your own admission that risk is slight. Is there a correlation? I haven't seen any. All I've seen is an urban legend with no supporting facts.

Does your hypothesis seem reasonable? I think it does...in a handful of situations.

Aftermarket and incorrect fluids are irrelevant to this discussion. If they result in transmission failures we're no longer discussing if changing the fluids is risky but rather using the correct fluids results in failure. My assumption in this discussion is the correct fluids are used and the fluid is change properly. Under those circumstances I (as well as you) see little risk in changing the fluid and potential upside. Y outweighs X easily. And until I see data showing otherwise I'll continue to conclude transmission failure from properly changing the fluid is nothing more than an urban legend.

And since BMW can't take it's head out of it's ass and stick w/ one answer, I'm still going to keep doing them at 50k for my own sake.

Because, to use the same logic as I provided you for the transmission, in the case of the engine oil x approaches zero, and y is significant. Engine oil is designed to be drained, a drain is provided, draining doesn't cause other problems, etc. Not changing engine oil impacts engine life. The fluid doesn't wear out (oil is slippery for its entire lifetime, as I am sure you know) but it gets contaminated by byproducts of combustion, and the additive package gets depleted. Comparing engine oil to transmission fluid is nonsensical. It would be much better to compare transmission fluid to shock absorber fluid, they are both hydraulic oils in sealed systems. You could change your shock oil I suppose; many years ago we used to rebuild shocks, particularly lever type shocks. Now they have lifetime fluid in them. Not your lifetime, the shock absorber's lifetime. Maybe that is a plot to get us to buy more shock absorbers.

How are you going to properly change a fluid that isn't designed to be changed? How are you going to drain it all?

For you, Y outweighs X. That is reasonable. For me, it doesn't, and I generally know how to work on the vehicle, and how to obtain the correct fluid. I provided the X and Y framework to try and move this into a more reasoned discussion. You see X as very small, I see it a little larger. You see Y as large, I see it as practically zero.

You keep calling X an urban legend, but that is insulting. My decision is based on over 25 years of relevant work experience, shop experience, oil lab experience, my mechanical engineering training (including tribology courses), and years of service management. The phrase urban legend puts all that in the same category as the yeti. You certainly don't have to agree with everyone, but you should at least respect other's opinions.

Jesus christ, this is the most beatin to death topic. At the end of the day, its a fluid...NO fluid is lifetime, so why in the hell wouldnt anyone want to replace it. Even BMW (because they are the holygrail ya know) has even revised their own suggestion of lifetime because they realized the err in their ways. Its now a serviceable item on newer cars, so why wouldn't we retro that same new practice to older cars...which are WELL known to have transmission issues. Sure, no one can prove beyond a reasonable doubt one way or another if changing vs not changing the fluid is a factor is transmission failure, so I revert back to my original statement - absolutely NO fluid is lifetime. Comparing a shock absorber and its 1 moving part to a transmission and its countless moving parts...now that is nonsensical. People...either change your fluid or don't, do whatever makes you happy. If someone wants to follow the (imho) blind advice that BMW has since stopped practicing, that's up to you. I know what I'm going to do, and its far less expensive to do every 50k vs a $4k transmission replacement. There will be just any arguements for as there are to not change it, so to each their own. How the OP turned the title of this thread and combined a transmission poll is beyond me...good job man, see the pot you've stirred ;)

You can either use an off-the-shelf internal engine cleaner from your local autoparts store, WalMart, etc or you can even use ATF...Google for the ratio as I'm not sure. Just be prepared for all the sludge to dislodge itself and possibly expose leaks that were plugged by the sludge before- valve covers, oil pan, etc.

Sure it is, but that is why it is called a Discussion Board, not a reference library. Sunny is new here, and hasn't participated in the discussion previously, so he gets to discuss it. We all agree there is no one single answer, so no need for the angst.

I know you are discussing using ATF in the engine to clean it out (and it works very well for that), but be careful as your caution about moving the particles around is pretty applicable to what happens when you change transmission fluid as well ;)

Yes, I know you recommend changing transmission fluid early, before anything collects there, but the humour struck me.

When I spill oil on my garage floor, I don't pour more oil in an effort to break it down and clean it up. I use a degreaser to break it down. Pouring ATF inside of an engine is going to breakdown the sludge that was caused from either improper oil type or servicing intervals. Draining and refilling the transmission w/ new ATF isn't adding a fluid that will cause breakdown of a dissimilar fluid because it's the exact same fluid. The only thing I'm doing is diluting the old fluid and making it stronger by adding new.

I understand where you're coming from in regards to dislodging sediment, sludge, etc...but that's my whole point. In either the engine (like the OP experienced) or the transmission...change the fluid frequently enough before it has the chance to collect and cause buildup issues, then it's a moot point. I've done plenty of transmission fluid and filter changes over the years, both on my own and customers vehicles. The amount of particules taken off the magnets tells me that all that metal floating around is just honing the fluid passages and making them larger, just like the Extrude Hone process people do on intake manifolds, throttle bodies, etc. Opening those passages, wearing away on the checkballs, and eventually clogging the filter as well is what (in my belief) is causing the transmission issues. I change the fluid before the transmission has a change to basically eat itself alive.

This is the way I see it...don't change the oil enough, and you'll be replacing your engine sooner than later due to fluid breakdown, sludge, premature wear due to poor lubrication on metal parts, etc. The same applies to the transmission, and I don't see why people find the transmission an exception to that rule. That's just my logic, but once again...to each their own. Naz24 mentioned that his SA said BMW has revised lifetime to be 100k. For the minor cost of fluid and filter vs an entire transmission and the labor involved to replace it, I still suggest 50k to all my customers.

I'm new here but I've been aware of this urban legend for quite a while.

You're ignoring the flip side. Perhaps there are many transmission failures which have been avoided because the fluid was changed.

Whether changing the fluid has benefit or not is, IMO, a moot point. If there is no downside, and none has yet been provided, why not spend a few bucks doing it?

ATF doesn't break down the sludge and move it around because it is a dissimilar fluid, it is because it has high levels of detergents (to make it last longer). ATF is just a lighweight oil with friction modifiers, detergents, and so on.

I agree that if you do it often enough, you will minimize the risk. You don't necessarily change the value equation, but you do minimize the risk.

I don't understand your point about all the metal particles in the fluid honing out the valve body. The fluid in those passages is essentially static, the fluid isn't coursing through there. Those are activation circuits for lack of a better phrase, or control circuits, not bearing journals.

I think the debate is coming to a close this time though, as Sunny just suggested that any benefit is moot, so one should just spend the money anyway. Not sure I get that logic, but what do I know? :thumbup:

For those that haven't read it, this was one of the better threads on the subject: http://www.xoutpost.com/bmw-sav-foru...intenance.html

I'm not going to argue if there is a benefit or not. Anyone who doesn't believe in lifetime fluids will see a benefit in changing the fluid.

There are two reasons why you would not want to chage the fluid:

1. You see no benefit to doing so.
2. The risk of doing so outweighs the benefit.

I have seen no evidence to support either of the above is true so I recommend replacing the fluid.

Hope that clears up the confusion my statement caused.

The difference between us is that I do think there is a downside to changing the fluid for the first time at higher mileage, so does JCL, who not only has personal experience working on transmissions, but also has extensive knowledge in lubrication and mechanical engineering, etc. Also, don't forget about Weasel (current tech at a BMW dealer as well as prior trans shop work), motordavid (family member is AAmco owner), and others...

I have actually heard of shops/dealers baulking on changing the trans fluid even when the owner was ready and willing to pay for the service. It seems like some of these places don't even want to touch the trans incase something happens after the fluid change. That way the owner can't blame the shop for the failure.

Good link. I missed that one. :thumbup:

That's fine. I do not. And without evidence to the contrary it will remain an urban legend in my mind.

I've spoken to my mechanic, who has 25 years repairing BMWs, about this issue. He doesn't feel there is any risk to changing the fluid. And he has done it many, many times.

Even JCL has qualified the risk as slight.

That is their right. I'm not surprised to hear there are some shops which believe this urban legend.

I have seen no evidence. What I have seen is a theory put forth by JCL. Of which he has refused to provide data in support of it. While his theory sounds plausible I believe it is so only in a handful of incidents. Unless he wishes to provide supporting data or reference to some other supporting data I will continue to view this as nothing more than an urban legend. And if calling it such leads you to conclude I'm being disrespectful, well, there's nothing I can do about that.

sunny, Are you a BMWCCA member? If so, I HIGHLY suggest e-mailing tech-talk and getting a copy of their old school maintenance schedule. It is written by Mike Miller who is more than likely a better BMW mechanic than your guy seeing as he does the mechanical questions for both Roundel and Bimmer magazine. In the maintenance schedule, he flat out states that it is risky to drain a previously unmaintained automatic transmission with higher mileage. Pretty much stating what everyone else here is trying to tell you that he has personally seen TOO MANY properly functioning automatic transmissions go shortly after a filter and fluid change. Shifting of sludge is just one of the reasons he states it can happen.

and like JCL pointed out, he goes on to say that he has seen properly maintained transmissions break anyway and that there is just no predictiing them. He says he has seen un-maintained as well as properly maintained units both go 200k. Unfortunately, I can't post this PDF from the CCA as they ask you not to, but you can obtain a copy with your $20 membership. There is over a page dedicated to automatic transmission maintenance. Maybe you could print it out and take it to your mechanic?

Pretty much like we all have said in this thread. There is no right answer when it comes to changing the trans fluid and you should do what makes you happy, but calling the risk of changing fluid on a higher mileage BMW that has not been maintained an urban myth, is just flat out inaccurate.

So with everything you said you couldn't point me to one piece of evidence?

Look, I'm not saying there is absolutely zero risk with replacing the fluid. As with anything there is a risk. I have repeatedly acknowledge there is some risk. And, like JCL, I feel that risk is slight (that is his qualification, not mine).

As for my guy he owns his own business and has been doing transmission fluid changes for years. I think he's more than qualified to have an opinion on the subject.

Also stating fluid changes have benefit is not the same as saying you will never have a problem with the transmission. That would be akin to saying that changing your engine oil will result in zero problems with your engine. I don't think any of us would say that...do you? So why would you make the same argument with transmissions?

Perhaps if you explain why new transmission fluid is likely to dislodge sediment whereas old fluid will not maybe I could see the risk changing from slightly to a more likely possibility. Can you do that?

JCL also alluded to thinner fluid and improperly performed fluid replacement. Perhaps the issue has more to do with incorrect fluids or work being performed than it does with merely doing the work. My assumption is the correct fluids being used and the work being done properly.

I also like Mike Miller and rarely disagree with his take on things -- he obviously is extremely experienced with BMWs.

Now, I don't particularly want to get into the middle of things, as AT fluid change is almost as controversial as which brand of engine oil and how often to change it, but there is a piece of information I'd really like to know if anyone has the answer.

Did BMW change their recommendation for AT fluid changes from Lifetime/never to 100,000 miles? I seem to recall reading that, but can't find a confirmation with a search.

P.S. For anyone who hasn't gotten enough of the AT change discussion, this link should keep ya' busy for a while! ;)

Collecting Statistics on BMW auto transmission and Lifetime ATF - Bimmerforums - The Ultimate BMW Forum

This thread is beating a long dead horse, but perhaps it's still an interesting discussion with some very valuable information. Let me just interject a couple of my observations/concerns:

1. I think there is certainly some strong credibility in the don't change the fluid in a non-maintained transmission, the question is, just what constitutes a properly maintained transmission where one wouldn't be at risk, or at least significantly lesser risk, of dislodging sediment? IOW, what's the magic cut-off mileage or age? Regular 10,000 mile changes, 15,000 mile, 20,000 mile, yearly, etc? With this I think I'd be more interested in hearing from ZF than BMW.

2. Given that BMW specifically states lifetime fill on the transmission, one concern I might have is that if I did change the fluid, and something went wrong with the transmission, would they cover it under warranty since they specifically said not to mess with it?

3. Not to add a 3rd component into the mix (engine oil, transmission fluid, and now...) but beginning 2004 model year BMW suddenly went to lifetime fill for the cooling system. Marketing decision? Does it fall under the same circumstances as transmission maintenance, etc?

4. While BMW seems to be gradually moving to completely maintenance free cars (at least on paper, especially when you are on a 3 year lease!) it appears that as newer engines come into play they are stepping up some maintenance schedules. Here is an interesting list of the 2011 model year maintenance schedules just as an FYI...

For the 335is (Coupe and Convertible), Z4 sDrive35is, and 740i/Li with the N54T engine:

• There is no 1200 Mile Service.
• Engine oil is the same as for the 335i (recommended: BMW High Performance 5W-30 Synthetic oil P/N 07 51 0 017 866)
• Spark plug replacement interval is 45,000 miles or at every 3rd engine oil service.
• Engine air filter replacement interval is at every 2nd engine oil change.

For the 135i (all versions), 335i (all versions), and 535i with the N55 engine:

• Spark plug replacement interval is 60,000 miles or at every 4th engine oil service.
• Engine air filter replacement interval is at every 2nd engine oil change.

BMW ALPINA B7:

• There is no 1200 Mile Service.
• Spark plug replacement interval is 30,000 miles or at every 2nd engine oil service.
• Engine air filter replacement interval is at every 2nd engine oil change.

Vehicle check: Check the expiration date on the M Mobility System sealant bottle. Change the bottle if needed.

ActiveHybrid 7: Maintenance is comparable to a 750i.

Spark Plug Replacement Intervals

2011 Model Engine Interval (miles); coincides with every _ Engine Oil change

128i, 328i, Z4 sDrive30i N52TU 60,000; 4th

135i, 335i, 535i N55 60,000; 4th

Z4 sDrive35i N54 45,000; 3rd

335is, Z4 sDrive35is, 740i N54T 45,000; 3rd

M3 S65 37,500; 3rd (first oil change is at 1200 miles)

550i, 750i, ActiveHybrid 7 N63 60,000; 4th

760Li N73 60,000; 4th

BMW ALPINA B7 N63B44M1 30,000; 2nd

I am not sure what type of proof you are looking for? What will it take? Mike Miller is the technical editor for BMWCCA's Roundel magazine. The BMWCCA has over 80,000 members. He answers up to 50 technical questions per day (according to himself) and about 3-5 pages make it into the magazine every month. He is also a contributing editor for Bimmer magazine where he answers additional technical letters. I think he did, or currently does, the same for European Car as well. Basically, I am saying that his data base dwarfs your mechanic's. Therefore, he should be better able to analyze trends, especially where BMW's are concerned. Like I said before, I wish I could post the entire PDF, but I cant. In it, he states very clearly that he has seen all too many times where where a well-meaning owner or technician performs an ATF and filter service on a neglected but well-shifting automatic, and then all of the sudden it starts slipping. He goes on to say that he feels a contributing factor of this is that the fresh ATF flushes a bit of sludge from a place where it was doing no harm to a place where it does do harm. He also see's overfilling, underfilling, and cleanliness as issues.

He also goes on to say that the fluid in BMW's "lifetime fill" automatics is proprietary info and highly recommends that the a dealer performs this service as no one knows exactly what BMW's proprietary ATF is. As I pointed out before, he states that not even all dealers will want to touch the trans fluid, not just typical shops that are buying into the "urban legend" as you say.

You don't have to take my word for any of this. Become a BMWCCA member and you can have access to the full article in no time. I am glad that you are finally realizing the risk is real and is not simply an urban myth as you said multiple times before.

Also, with some BMW automatic transmissions seeing 200k+ miles on the original fluid (think we have a few here) as well as the dime a dozen 100k+ on original fluid here, the fluid itself is no the main concern. Like JCL has said, the other components are going to fail before the fluid and changing the fluid every 30k miles is not guaranteed to make the trans last any longer.

Yes, they sure did, but I am not positive when that was.

I'd have to double check but I know that from 2002+ it was 100,000 miles and not lifetime.

Coolant change interval went from 4 years in 2003 to lifetime in 2004+.

Meister, some good detailed information in your posts above. One comment would be that BMW can't be said to be changing their recommendations (which implies that the same engine or transmission is under discussion) if in fact the components changed from year to year. Your note shows that different engines have different maintenance recommendations. It isn't all about extending the intervals, it is about optimizing the maintenance cost when considering risks and other factors. If BMW are providing different recommendations for different engines (in the same model year) then that implies to me that the marketing department is not simply saying don't maintain them, but that the engineering department is saying that in this case, with this usage profile, with this engine, do the following.....

For most components, changing the fluid has little downside. For coolant, I would do it every four years, as the only downside I see is the environmental impact of disposal of the used fluid. You aren't going to negatively impact the cooling system. You can get coolant tested, but that is probably more work than reasonable.

The tranmission is the only component that I wouldn't touch, and it is due to the risk, which I have seen the consequences of. I know that I called it slight (Sunny keeps reminding me) but it is still greater than the offsetting benefit in my mind.

If I had a 100,000 mile warranty, and a 100,000 mile fluid change interval recomendation from BMW, I certainly wouldn't give BMW cause to deny warranty (when I fully expect the trans to fail anyway) by touching it. It is very easy to tell if a transmission has been opened.

Yes, it is a thoroughly dead horse, but I suspect some people are still finding out new information.

I'm not even going to bother responding to what you wrote as you're obviously not reading what I have written. From my second post on this subject I clearly said:

"There is the possibility of dislodging sediment but even if that were the case I have seen no evidence to support that dislodged sediment correlates to transmission failure. So while the risk is there I think a transmission failure resulting from it is so rare as to make it a non-issue."

And in my next post on the subject:

"I previously acknowledged the possibility of disloding sediment. However my personal opinion, and it appears it is shared by JCL, is the possibility of it happening is very low. Furthermore should sediment be dislodged I have seen no evidence it will result in a transmission failure. So the chances of dislodging sediment are very low and the chances of dislodged sediment resulting in a transmission failure are very low."

And my next post:

"There you said you felt the chances of dislodging sediment are slight. I agree with this."

And the following post of mine:

"We're in agreement there is a slight risk accumulated sediment can be dislodged."

And my next:

"It is your theory the transmission failed because of the fluid change but you cannot offer anything other than a theory. What is surprising is you continue to say there's a slight chance it could happen. Of which I agree."

And my next:

"Is there a risk? Most certainly."

Given I have repeatedly acknowledged the risk throughout this discussion but you seem to feel I haven't until my last post I see any further discussion with you as futile.

I would like to hear JCL and other's explanation as to why BMW did this.

:thud:

You admit to the risk, then refer to the risk as a non-issue and call it an urban legend over and over multiple times after the fact. You are clearly talking out of both sides of your mouth.

You keep asking for proof, but if someone as heavily involved in the technical side of BMW as Mike Miller doesn't convince you over your mechanic, then I don't know what to tell you. He states he has clearly seen too many of these failure cases. Too many isn't a non-issue or an urban legend to me. It may be to you though.

I feel as if I am wasting my breath on you. Carry on.

Last ditch effort here. From what I have read, they changed the definition of "lifetime" regarding the trans fluid because nobody knew what lifetime meant. Lifetime of the car, the component, the original ownership, etc. They threw a number on it to try and clear up some confusion. I have not heard that it was due to the fluid going bad, trans failures or anything related to maintenance. Pretty sure it had more to do with marketing and customer relations.

No, there's no double talk. There's a risk. However risk does not equal a problem.

Welcome to my conclusion of my discussion with you since you obviously were not listening to what I wrote.

Yeah but they went in the opposite direction with the coolant and you can ask the same question !?

It's a foolish explanation. What he's saying is BMW decided, for marketing purposes, to recommend a proceedure alleged to cause transmission failure.

That explaination comes from Mike Miller. :confused:

We are officially done here sunny.

Avus Autosport, Inc.Blog
 

Mike Miller's Alternative BMW Maintenance Schedule
Avus Autosport, Inc. Blog Mike Miller Alternative Maintenance Schedule

...which basically says to either change it every 50k (which I've suggested since day one) or play the odds and leave it be. For those who haven't changed it, then it's on you and it's simply a choice after that. Some have had luck changing the fluid in the 100k range w/ no ill effects and reported better shifting. Some have even changed fluid when they had shifting issues and it solved the problem. Some have also changed the fluid and had failures within days, weeks or months. It seems there is no definate answer, but since I've had no issues changing at 50k, which I've always done, then it's my conclusion that it shouldn't be an issue as long as it's maintained sooner than later, not waiting till issues have already risen.

You can't correlate oil, trans fluid, coolant, and brake fluid, and say that they all have the same issues. They don't. They have different failure modes, entirely different compositions and purposes, and so on.

Lifetime coolant, to me, means it had more additives in it to prevent foaming, etc. While you could leave it in for a very long time, changing it every four years seems reasonable, given that there is no real downside. Maybe they decided that water pumps go out after 5-6 years, and that is the definition of coolant lifetime, I don't know.

Strictly as an example, if you leave your brake fluid for four years, you will likely experience stuck calipers (see the recent posts on the subject, likely related to vehicles where owners ignored the two year flush interval).

I don't understand why different fluids are being directly compared.

BMW decided, for marketing purposes, to sell M vehicles in a country with 65 mph speed limits. Speeding is a procedure alleged to cause bodily harm. However, they probably figured they could move a few vehicles, and make a dollar. Good for them. What was your point?

My point is, if we're told hold your assertion true to any reasonable degree, then BMW is recommending to their customers a needless proceedure that will result in transmission failure. Do you really think they'd do that for marketing reasons?

"No real downside" implies there is some downside. So, like replacing the transmission fluid, why would you risk it?

You've got it backwards. The only way you would know sediment was dislodged, and that it mattered at all, is when you do have a transmission failure. You are saying that there can be sediment moved, but so what? I am saying that the failure analyis of any failed transmission provides the type of proof you are looking for. Think about the valve body located in the pan of the transmission. It contains very small orfices, check valves, and control circuits. The failure analysis of a transmission that didn't shift properly (after a fluid change) has been found on too many occasions to include that famous sediment in the valve body, restricting a passageway. It isn't that sediment might get dislodged, and not hurt anything. We wouldn't even know if that happened. It is that if you analyze a failed transmission, and check which clutch pack or actuator stopped working, and then search for and find debris in that circuit that you can conclude that something caused the debris to move.

The photo attached isn't a ZF, but it will do. There is a spool valve at the top left, and there are multiple check valves (ball bearings with springs). The passageways are about the size of a pencil lead. Also, the fluid is somewhat static, so what gets stuck doesn't get flushed out easily.

Sorry, that is the best I can do for an explanation. Photo attached.

That's a slippery slope to start on -- if BMW can change their AT fluid change recommendation from Lifetime to 100,000 for marketing reasons, even if it is unwise to change ATF for the first time at 100,000, then who's to say they didn't originally change it from 50K to Lifetime for marketing reasons, even if that was unwise?

Once one accepts that BMW maintenance requirements and intervals are influenced by Marketing, and not just Engineering, it sort of kills the argument that "BMW Knows Best" when it comes to maintenance requirements.

I'm still waiting to see where BMW changed their recommendations for fluid changes. They never did with any BMW that I owned. I can't imagine them wanting to take on the liability if they did want to change the interval.

What they did do was come out with newer models, with new transmissions, with new fluid specifications, which have different change intervals than previous models. Those posters who never liked the old recommendations have adopted the new ones, even for older vehicles. To me, that is like doing 15,000 mile oil change intervals on an older vehicle that was designed for 7500 mile intervals. It is cherry picking. The recommendations that matter apply to the specific vehicle in question.

Now, does marketing have a part in all this? Certainly, as they will have suggested to the engineers that it would be great if they could advertise lower maintenance costs. But to claim that marketing made that decision without any say from engineering at all seems silly. Look at Meisters post above about the engine-specific recomendations now coming out. I don't think marketing has much of a role in those decisions.

I certainly don't think that BMW knows best about all maintenance practices. I think they have a good framework, a good starting point. Those who don't agree with BMW recommendations accuse some of us of blindly following BMW guidelines. Personally, I like to understand the guidelines, use them as a starting point, and go from there.

When BMW first said not to rotate tires, many years ago, I was suspicious. I had rotated tires for decades. So, I watched my tires very closely, and had over 70,000 km on the original tires, with very even wear, when I sold the vehicle. So, I guess they were right. Sometimes we have to adapt our thinking.

Again you're arguing as if I've made the argument that it will never happen. That's not the case. As the post you responded to shows I've clearly acknowledge it can happen. So will you please stop tearing down that strawman of yours?

With that said I have seen no data to correlate transmission failure with fluid replacement. You say you have some but when asked to provide it you balked. You're own qualification of it happening is "slight". You can't say it's slight and then argue it's more than slight. Pick a side and stick with it.

The fact you've seen transmission failures shortly after the fluid was changed doesn't automatically translate into the fluid change being the cause. There are many factors which could have resulted in the failure. From your own argument some of those factors could be: Incorrect fluid and improperly performed work. Other factors include an owner attempting to fix a more severe problem with a fluid change. I would suggest this latter being more common than a fluid change resulting in the failure. Or maybe the thing was just going to break regardless of the fluid change. Without any data we can't narrow it down to any one specific reason.

Personally? Because I have the experience to know how to change my coolant, bleed the system, and so on. I can manage the risks, and thereby mitigate them. That is something that I can't do with a transmission fluid change, unless I remove and tear down the transmission as part of the fluid change (which would be silly, since it is purportedly what we are trying to avoid)

The downside I was thinking of was the environmental disposal risk of the old coolant. It is a negative, but manageable.

I agree with you and your points; you can't correlate those fluids, and I am not comparing them. I think you misunderstood my comment. What I was trying to say is that some people speculate that BMW painted themselves into a corner in calling something "lifetime fill" and so to get out of that corner they changed it to "100,000 miles." My point is that I don't that's quite what happened since BMW clearly did just the opposite roughly around the same time, albeit for a different fluid (that actual fluid not being the relevant point of my comment).

IOW, they got themselves out of a corner (lifetime ---> 100,000) but then put themselves right back into a corner (4 years ----> lifetime) !?!?

Hope that makes sense.

I can agree with your logic. The whole point of my first post in this thread was just to let people know that there ARE risks associated with doing so on an un-maintained automatic trans with higher mileage. It seems important for BMW owners because many people do follow the factory maintenance program, which means there are a ton of BMW owners who either haven't changed their fluid or are planning on doing so for the first time at 100k. Unfortunately, these people fall into the catagory Mr. Miller describes where he has seen many fail after the change. That is all I wanted to point out. I didn't realize this myself until a year or two ago. I was under the impression that new fluid would be 100% beneficial with absolutely NO downsides what so ever. Seems that isn't quite true.

If I buy a low mileage car with an automatic transmission , I will consider changing the fluid out regularly, if nothing else than to make mysellf feel good. My X has 112,000 miles, so I am not going to touch it at this point. Might as well put that money into a rebuilt transmission fund instead.

My next car is going to have a manual anyway, so most of this debate will be inconsequential.

I am not going to provide you with data which isn't mine. Sorry.

You are choosing which words to focus on. I said it was slight, which means that it happens sometime. I called that X, earlier. We both seem to agree that X is more than zero. I said it was more compelling than Y. Now, where is your proof for Y, namely the benefit of changing the fluid, being anything greater than zero? Motherhood isn't a reason, just like hope isn't a plan.

I am basing my judgement on my experience. You seem to be basing yours on internet debates.

You use the phrase strawman, but then you provide all these tangental causes that have nothing to do with the debate. Let's stay on point.

Recommend you consider an applied failure analysis course. They taught us to look for root causes, and not be bullied by opinion.

I believe you are right. When I said they changed from "lifetime" as in never to "lifetime" as in 100k miles, I wasn't necessarily saying that they changed the interval for specific models, but rather that the interpretation of "lifetime fill" changed at some point. I think it happened somewhere from the mid 1990's-2002 or so.

Makes perfect sense :thumbup:

In the maintenance procedures checklists going from year to year you can easily see how and when changes were made. i.e. brake fluid 1 year ---> 2 years. Coolant 2 years ---> 3 ----> 4 ---> lifetime. etc.

Here's one example using coolant.. At the top is the maintenance procedure for 2002 X5's. In the middle for 2003. At the bottom for 2004, 2005 X5's. Similar information can be found if you compared details in service booklets from model year to year.

I remember first noticing this sort of thing year ago when they went from yearly brake fluid changes to q2 years. I had always done it yearly, and never thought about deviating from that schedule, but like JCL put it maybe there was something to it that I didn't know. So I got a brake fluid tester (FTE) and measured the brake fluid every few months. At around 14 months although the fluid was noticeably darker, it still measured less than 2% water content which was acceptable and according to the tester, not requiring a change. Nevertheless I still had it done under free maintenance.

So the risk exists and is real. Applying the same logic you use for the transmission fluid you would never change your coolant.

How to put this nicely.....You appear to have a reading comprehension challenge. Look up the word mitigate, and then see if you want to edit your post, above.

What do you mean it's not yours? Didn't you argue, based on your experience, that changing the transmission fluid is likely to result in a transmission failure?

X is greater than zero. And Y is greater than zero if you don't buy into lifetime fluids (do you?). The question is: Is the benefit of Y greater than the risk of X. I believe it is.

Why there is that experience referenced above. If you're going to argue your experience then you're going to have to provide the supporting data behind it. You can't have it both ways.

As for what I'm basing my argument on it's not based on internet debates. It comes from a number of things:

1. My mechanic who has been working on BMW for 25 years and has performed numerous transmission fluid changes without any failures as a result.

2. The fact there is no such thing as a lifetime fluid. We change every other fluid in our cars so why would the transmission fluid be any different? We know fluids become dirty and break down with use and age. This decreases the protection they offer.

3. The service recommendations of other manufacturer transmissions. Automatic transmission essentially all work the same way. Why would BMW transmissions be ommitted from fluid changes whereas other manufacturers would not?

There's nothing tangential about them. Is it your opinion the wrong fluids could not cause failure? Or improperly performed work could not result in failure?


I'm trying to find the root cause but so far you've avoided providing it. The claim is yours therefore the burden of proof is yours.

Mitigate does not mean eliminate. Which means there's still a possibility. Exactly as with the transmission fluid change.

Anyway I see no further point in discussing this with you if you're going to engage in ad homs. You have your opinion and I have mine. Until you, or someone else, can show supporting data for your claim I will continue to view this as nothing more than an urban legend.

Urban legend or not, there is certainly a very real possibility that BMW could deny you warranty repair on a transmission you opened when they told you not to. Have a go at your nav system and when it craps out see what they say. It only costs half as much as a transmission anyway.

Does that mean I am at risk of having my warranty denied because I change my engine oil more often than they recommend?

Honestly I don't know, but it's certainly something to think about.

On what basis would the denial be based?

I don't understand your question?

What would be the reason for BMW to deny a warranty claim on the transmission?

That it was opened when it wasn't supposed to be. (Seems pretty obvious)

If it's not supposed to be "opened" then why would BMW recommend it be "opened" at 100K miles?

Data belongs to the owner of the vehicle and/or the shop, not me. As an aside, I see little benefit in providing you data because you have repeatedly twisted the arguments to suit your own purposes.

And no, I never suggested that changing the transmission is likely to result in a transmission failure. I suggested that it is more likely to do so than it is to provide a benefit. Please review the above posts.;)

I am very happy for him. I guess that must be a very large sample size. I bow to his expertise, and your unwavering faith in him.

That is simply nonsense. When discussing lifetime fluids, please confine your examples to sealed systems with no outside sources of contamination. I suggested a shock absorber, but James didn't like that one. The issue isn't whether it gets dirty and breaks down; the issue is whether it does so before the transmission fails of other unrelated causes. Why is transmission fluid different than other fluids? Already explained it, sorry it wasn't in a form that was comprehensible.

You seem to think this is a BMW issue. Sorry, it isn't.

No, both are obviously possible, but as I already explained above, those particular examples were already discounted. They aren't a causal factor in the examples I am referring to. You are simply bringing up non-related points to confuse the issue. You need to come up with something new here.

I gave you the root cause, you just choose to believe your mechanic over others here. But since we don't know who he is, and he isn't here, I guess we will just have to take his opinion as fact.

Unlikely, if you use an engine oil and filter that meets BMW specifications.

What the hell is wrong with you? Read and re-read post # 92 at least 50 more times. There's the answer to your question.

I read it before I initially replied. And I just re-read it on your recommendation. I fail to see why BMW would deny warranty coverage based on changing the transmission fluid.

The only reason given is that they would deny it because it was "opened" (I assume this means the fluid was changed) based on the false premise it's not supposed to be "opened".

In the example you are proposing, the transmission fluid is presumably changed prior to 100,000 miles, by a non-BMW shop (since BMW shops are unlikely to want to do it, it being a non-recommended procedure and all).

If the transmission failed soon after this, most manufacturer warranty adjusters would pin the blame on the fluid change, which makes it more of a service warranty issue (quality of service work) vs a parts warranty issue (original parts manufacturing defect issue). Think about it. The burden of proof is on the service shop that did the repair to prove that they didn't initiate the failure. They were the last to touch it. What many owners don't realize is that their transmission isn't in any way guaranteed to run 100,000 miles (if that is in fact their warranty period). It is guaranteed not to evidence problems caused by the original manufacture of the parts, for that term. I am leaving out the prepaid maintenance work here, if that applies, and focusing on the warranty itself.

In the event of a failure, your comeback would be to whomever performed the service work, with the claim that their work initiated the failure. You likely have a warranty claim, just not with BMW. Most shops will guarantee their service work for one or two years. This is precisely why many shops will decline to change the transmission fluid even when asked, unless they have the owner's agreement that a subsequent transmission failure is not claimable.

You are answering your own question yet you don't realize it.

As I said before, I don't know for certain, but one can certainly at least imagine the possibility that ...

1. You have a transmission that says lifetime fill on it, or 100,00 miles, whatever.
2. BMW doesn't want you to screw with it and open it.
3. You decide to change the fluid x times between 0 and 100,000 miles.
4. It craps out for whatever reason.
5. BMW looks at it and notices that someone's opened it.
6. BMW checks their records which shows that it wasn't opened by BMW.
7. Heads get scratched.
8. Now, because BMW doesn't know what you did to it when you opened it up, which again is something they didn't want you to do in the first place, it seems they have a pretty good reason to at least speculate that you didn't know what you were doing and busted it.

Again, I have no idea if this would ever happen, but it certainly isn't random speculation. They produced a pretty sophisticated device which 99% of people don't understand how or why it works or how best to maintain it and they don't want you to maintain it. They will maintain it for you...at about 100,000 miles. Given all the speculation and quite a bit of experience from others on the board that shortly after a maintenance like that it will crap out, it seems to me your best protection is to buy a 1 year extended warranty and if it does break they fix, or rather replace it. They certainly can't blame you for not adhering to their maintenance schedule.

Electronic components are typically sealed for this exact same reason. Break the seal and then want free warranty repair? Good luck chuck.

Clearly I type slower than JCL. Damn.

:rofl::rofl: Used to be 100-120 wpm. Not sure now. As an aside, it is probably why I don't understand the need for tablet computers (another thread currently running).

It's unlikely they'd deny the claim because the fluid was replaced but because the work was performed at a non-BMW facility. This isn't unique to replacing the transmission fluid.

Irrelevant. They (BMW) would (likely) deny the component (transmission) claim.

You could conceivably have a service work claim against the shop that did the work, but it doesn't matter if it is a BMW shop or an independent. In either case, we are not talking BMW warranty, but rather service warranty. Dealer service warranty is not the same thing as BMW factory warranty, which was the subject.

This statement is pure fiction or fantasy, you decide. You have ZERO idea whether they would accept or deny it. And frankly THAT'S MY POINT. We are not talking about a $50 part here that they will waive the cost of without blinking an eye. We're talking in the neighborhood of a $6100 + tax transmission. So why take the risk?

Also do the math:
Filter $55
Gasket $32
Plug + washer $5
Fluid 9.5 quarts @ $170 / gallon ==> need 3 gallons = $510
Oil transfer pump $20

Conservative total w/5% tax = $653.00

Versus
1 year/12,000 mile BMW powertrain plus extended warranty = $1340

So you can change it twice or just buy a warranty for the same amount for a year. Something to think about.

New questions for Sunny:

I wondered idly how many posts had been made in this thread, so I looked up your posting history. Practically all posts are on this topic, but you did post that you had a valve body failure in your 2000 X5. Sorry to hear, it sounds like it was expensive, and it was out of warranty. Valve bodies don't typically fail in normal use, unless they get clogged. So here are the questions:

Had you or your mechanic changed your transmission fluid at any time prior to that transmission valve body failure?

If so, do you think the fluid change could have contributed to that early failure? If not, do you think that changing the transmission fluid would have extended the life of the valve body?

Just wondering.

I can see the arguments on both sides, but at the end of the day I think I'll go with Mike Miller's advice, simply because I've got a lot of faith in his experience and expertise:

"The short answer for the modern BMWs with “lifetime fill” ATF: Change it and the filter at least every 60,000 miles using ONLY the factory BMW proprietary ATF."

He might be wrong, but from what I can see his track record on other topics seems to be rather good.

I can make an informed reason why they would deny it if they did. And, it's likely the reason would be because the fluid was changed at a non-authorized BMW service facility and not because the fluid was changed. This would likely apply to almost any other type of service you might do on the vehcile.

It's well known that in order to avoid this potential problem you have an authorized BMW service facility perform all service while the vehicle is under warranty. As I said already: This is not unique to changing the transmisison fluid. As a matter of fact it has little to do with changing the fluid (other than that was the work performed).

You don't. If you want the transmission fluid flushed while it's under warranty then take it to an authorized BMW service facility.

Do you realize his advice came back in 2002?

This is also why some choose to not to have two or three changes by 100,000. You would be looking at about $1,300 to $1,950 for two or three changes and you still have the possibility of a trans failure. Might as well put that $2,000 in the bank and roll the dice.

:popcorn:

I sent him an e-mail in December asking for his maintenance recommendation document and that is in the document he sent me. Since he is quite emphatic that he does not want his maintenance document posted on the internet as he does not want any out-of-date copies floating around, I assume what he sent me in December is still an active recommendation of his... at least as of December, 2009.

P.S. I just checked the document he sent me, from which I took that quote. It has a "revised" date of July 2009.

Since you are the US, why wouldn't you just use the provisions of the Magnusson Moss warranty act that restrict tie-ins during the warranty period? BMW can't require that the required service be done at their dealer, just that it be done.

It isn't about where it is done, it is the fact that it is done.

:iagree:

I mean come on...head technical editor of the BMWCCA. Enough said.

Oh, and just so everyone knows, one of the other reasons Mike doesn't want people posting his schedule online is because it is because it constantly evolves and changes with the times. The copy on the link may have been dated, however, the newest copy (as of a few weeks ago) basically says the same thing. :thumbup:

Oh what the hell:

• Had you or your mechanic changed your transmission fluid at any time prior to that transmission valve body failure? No.

The vehicle had approximately 85K on it. To my knowledge the fluid had never been changed (though I bought it with 80K on it). My mechanics cost on the part from BMW was $1,800. My mechanic ordered it directly from ZF (we have a local distributor here in Denver) at a cost of $550. He passed that cost along to me with no mark up. After the work was completed the problem was fixed.

My mechanic knows his stuff and goes out of his way to treat his customers fairly. This is one example.

Edit:

• If not, do you think that changing the transmission fluid would have extended the life of the valve body? There is the possibility. And since you said "Valve bodies don't typically fail in normal use, unless they get clogged." It seems reasonable to conclude you would agree with me.

The point is it's based on dated information. Whether the current document says essentially the same thing is irrelevant. His opinion on the matter was formed over seven years ago.

Meanwhile the manufacturer has since changed their policy and now recommends the fluid be changed every 100K miles.

Damn, I guess I am a slow typer as well. :rofl:

My copy is even more recent...

If you take this advice, and I personally highly respect Mr. Miller, then you should also realize this is no drain and fill job. It needs to be done at the right temperature, in the right sequence, in a environment that needs to be far cleaner than for a basic jiffy lube oil change, the transmission must be cycled in a specific manner. It needs to be meticulously investigated for leaks, etc. This is no chip shot. Just an FYI.

Glad to hear it. I like to think I treated my customers fairly as well.

So, you had a transmission failure at 85k that a fluid change did not precipitate (as far as anybody knows). Now, the second question was do you or your mechanic think that regular fluid changes would have prevented the valve body failure? (sorry, I don't know the failure mode, or I could form an opinion)

How in God's name you don't understand my point I just don't know.

Think of it like the nav computer. They seal it and don't want anyone screwing with it. Doesn't matter who. Not you and not an indy. If you, your indy or Indiana Jones decides to open it up to 'fix' what ain't broken and it then breaks you cannot expect them to foot the bill.

No more. I'm done here. On to the who has more belly button lint thread...

Well, at the end of the day, I'll still take Mike Miller's opinion. From what I have seen, he knows his stuff. Frankly I think it is unjustifiably insulting to him to flatly state that his opinion was formed seven years ago, is based on dated information, and that "Whether the current document says essentially the same thing is irrelevant."

Aren't all the opinions stated in this thread based on the same "dated information," since we obviously do not have long-term statistics on the newest transmissions?

Are you seriously suggesting that posters on this thread have more data, feedback, or information on BMW transmissions than Mike Miller?

In any case, when I do not have enough information or experience to make a definitive analysis on my own, I have to pick someone to believe. And in this case, I pick Mike Miller.

Others can choose someone else if they feel they know more than Mike in this area.

Again the implication of the work being done incorrectly. Which is a real possibility. Which says nothing about it being a problem if the work is performed properly.

I am thinking this:

1. The manufacturer recommends the fluid be changed at 100K miles.
2. My mechanic recommends the fluid be changed. Though I don't know what his recommend interval is.
3. JCL and Mr. Miller both say there's slight/minimal risk.
4. I have seen no supporting data to show a correlation between changing the tranmission fluid and subsequent transmissions failure.

I hear that there is a mechanic in Denver Colorado who is pretty good. :thumbup:

The problem is they recommend you "screw with it" at 100K miles. That's where your reasoning breaks down. What part of that are you not understanding?

Did you actually read the Mike Miller quote I posted? Mike said he RECOMMENDS that the fluid be changed at least every 60,000 miles.

Mike also states:

"It is risky to drain a previously un-maintained automatic transmission with high mileage, even though if it were my car I would probably chance it."

I guess I don't understand why you are seemingly disagreeing with Mike Miller's advice.

Are you arguing that the AT fluid should not be changed?

If I knew him personally, I might go with his opinion. ;)

I read the link provided by BMWvoid. I assumed it was the same information.

I believe I've completely misunderstood your argument. Too used to seeing posts about Mr. Miller being used as support as to why the fluid should not be changed. I now realize you're using it in support of changing the fluid. My apologies.

When 50,000 miles rolls around, this is one task which I will most likely "bite the bullet" and have a BMW dealer do for me. Probably cost twice as much, but probably, in this case, worth it.

I think that's from 2002. :D

P.S. An interesting note... in comparing the 2002 document of Mike Miller with the 2009 version, it appears that, unlike your earlier contention that Mike "formed his opinion seven years ago," Mike has changed his position on changing ATF on a high-mileage AT transmission. In 2002 he said, "under no circumstances" would he do it, but in the latest document he says that while risky, he himself would choose to do it.

I think you owe Mike an apology more than me, as he clearly modifies his position over time when he feels it is appropriate.

Looks like FSETH and JCL lost a major piece of support for their argument.

Huh? I don't recall quoting Miller.

My apologies if I got you confused with someone else.

With that said, given Mr. Millers qualifications and recommendation are you willing to consider that your position may be wrong?

You should e-mail mike and ask for the latest version to get the whole story. He is not "black and white" on the ATF high-mileage change issue. Basically, he feels there is a risk to the high-mileage ATF change; however, believes the balance is in favor of changing it. But you really need to read his words to understand the "grayness" of the area. I'd offer to e-mail you my copy, but it appears even the 07/09 revision is now out of date, and he seems concerned about old versions circulating on the net.

I fully understand there is a risk in changing it. But I believe, as does JCL, the risk is slight.

The part where JCL and I disagree is if the benefit outweighs the risk. JCL believes it does not (because, as far as I can tell he doesn't believe it offers any benefit). I believe it does. Though recently it appears as if JCL believes there is some benefit based on the following statement he made:

"Valve bodies don't typically fail in normal use, unless they get clogged."

Very likely a fluid flush would avoid the valve body becoming clogged. I'm still waiting for his response to this.

And we can see why as someone was using an outdated copy to support this urban legend.

Do you even understand my position? I don't think you do. You don't even know my qualifications.

My position applies to my vehicle, not yours. There isn't a right and wrong, as I pointed out at the very beginning of this thread. There is a balance of risk. Penguin refers to it as not being black and white. You seem to want to make it so. Anyone who doesn't agree with your mechanic is discounted.

I don't particularly subscribe to Miller's recommendations, so he doesn't influence me. I don't necessarily disagree with him, I just don't read him so can't really comment.

If I had a high mileage X5 with a shifting problem, I would change the fluid because I would have nothing to lose, just the price of parts. It would be a faint hope clause/Hail Mary kind of effort. If I didn't have a shifting problem, I wouldn't touch the fluid. I guess I disagree with Miller there, if I understand his position from the summar comments posted. If a fluid change didn't resolve the problem, I would take the transmission out and overhaul it myself.

Now, what I really want to know is, do you even acknowledge that a likely cause of your valve body failure was a fluid change prior to you buying the vehicle? And are you now changing the fluid hoping to avoid another valve body failure? Or was your valve body failure one of those many transmission failures not impacted in any way by fluid changes?

It is the other way around, you have it reversed. The fluid flush tends to cause the valve body becoming clogged. It isn't common for a valve body to fail for other reasons, but I am sure it could happen.

Please don't keep assigning beliefs to me that you have erroneously formulated from various comments.

I fully understand your position. You feel the benefit does not outweigh the risk. Is that or is that not correct?

I believe you stated your qualifications early in the discussion.

I agree. I fail to see why you continue to feel I am not aware of this. You and I have a different opinion on the risk/benefit.

What I disagree with is a correlation between changing the transmission fluid and subsequent transmission failure. I have repeatedly stated there is some risk and because of that risk I'm sure there are examples of where sediment became dislodged and caused a subsequent failure. However that does not translate into a correlation of fluid change = subsequent failure...as you would have us believe.

And yet you seem to have ignored this as potential reason why you may have observed transmission failures after a transmission fluid change.


So how about commenting on my valve body replacement? Do you think a fluid change may have averted my problem?

No, I don't acknowledge it as likely. There is no evidence to suggest the fluid was ever changed. It had 80K miles on it and came with a considerable number of service records and none of them showed the fluid had been changed. Likewise there was no indication the fluid had been changed when the repair was performed.

Will I acknowledge there's the possibility the fluid was changed and thus resulted in the failure: You bet. Though I think it highly unlikely (or, the inverse of that would be "slight"...a word we've seen before haven't we?).

That's part of it. But not the only reason. I had all the other fluids replaced as well because I want to start with a known baseline and I believe no fluid is lifetime.

This is possible too.

No, I don't have it the other way around. You just said the VB tends to fail because it becomes clogged. Assuming the fluid wasn't flushed, and there's no reason to think it had, do you feel flushing the fluid would have prevented the failure? Seems reasonble to me the flush would have removed the contaminant and possibly saved me a lot of money.

I'll keep this in mind should it ever happen.

Is there a risk, or is it urban legend? I still don't know where you stand. You can't have it both ways. One or the other please.

There is a risk and it is an urban legend. The two aren't mutually exclusive.

Lets clean the slate and start over for a minute. What exactly is the point that you are trying to get accross in this thread?

I am saying there is no proof showing a correlation between transmission fluid changes and subsequent transmission failures. And that such a claim is nothing but an urban legend.

To help illustrate:

When changing the oil in a vehicle there is a risk the drain plug can be over tightend and strip the treads of the oil pan or plug. Just because this risk exists, and it has been known to happen on occasion, does not mean there is a correlation that changing the oil results in stripped oil pans or plugs. I would consider such a claim an urban legend even though the risk is there and I can point to examples of it happening.

OK, so would it be fair to say that you disagree with Mike Miller's, JCL's, etc. opinion that changing the fluid for the first time on an un-maintained, higher mileage (say 100,000 miles) automatic transmission comes with risk of failure due to the fluid? Keep in mind that I am not talking about someone using incorrect methods, techniques or fluids. I am talking about a perfect fluid and filter change with the propert parts.

No, it would not be fair to say that. I agree there is a risk. Why do you keep arguing as if I am not acknowledging there is a risk when I have clearly said there is?

With that said given there is a risk does that translate into an appreciable number of subsequent transmission failures? I have seen no evidence that it does. Hence the claim changing the fluid, while it carries a risk, results in subsequent transmission failures is an urban legend.

Well, with all due respect, when you say "there is no proof showing a correlation between transmission fluid changes and subsequent transmission failures. And that such a claim is nothing but an urban legend.". That sure makes it sounds as though because you have no proof, you don't think there is a risk and it is an urban legend. Do you see how it comes across that way? How else should one interpret what I quoted you on? I am really trying here, but read what you wrote and see if you can understand what I am talking about.

I know you are looking for diffinitive, written in stone proof and I don't really know how I can provide you with that. What I have done is provide you with factual info where BMWCCA's head tech guru has stated that he has personally seen this exact situation happen all too many times. He even gives his thoughts on why this happens. Yes, he does say he would probably chance it and change the fluid in his own car, but if you read the entire article, you can tell that the decision didn't come easy. It does seem like he did some hand wringing over the decision and this leads me to believe the risk is much greater than you are giving it credit for. Well beyond the percentage of urban legend.

So, to sum up; I am basing my info, which I have shared with you, on someone who has years of experience working on cars, is trusted by the BMWCCA, Bimmer Magazine and European Car magazine to feild technical questions and help diagnose problems, etc., other actual members posting in this thread as well as another long-term member who happens to be a tech at a BMW dealer and you are basing your opinions on some mechanic that none of us have ever heard of and that you have failed to prove actually exists. Am I missing something here?

I don't think you're trying at all. To go back to my oil change example. If I were to say changing your oil results in a stripped oil pan would you or would you not agree with that statement? Please explain why.

I am looking for more than anecdotes. I am looking for something along the lines of:

Out of 100,000 transmissions where the fluid was changed 10,000 of them exhibited a failure. Compare this with 100 (per 100,000) that failed where the fuild was not changed.

I am basing my information on my mechanic who has 25 years servicing BMW's who states he has observed no increased failures as the result of fluid changes. I am also basing it on the manufacturers recommendation to change it at 100K miles. I am also basing it on my phone calls today to three BMW dealers inquiring into a transmission fluid flush. None of which were reluctant to perform the work. In addition I am partially basing it on both JCL and Mr. Millers statement that the risk is slight (JCLs exact qualifier). And finally I am basing it the complete lack of any supporting evidence. I will remind you the person making a claim ha the burden of proof.

Out of curiosity, did they give you some price quotes?

Yes, ~$320, ~$360, and ~$370. But I was inquiring about my 328i so I suspect the cost would be slightly higher for the X5. The cost for my mechanic was $300.

Why wouldn't you ask about the car in question, which is the X5? What year is your 328i? e36, e46, e90? What are we talking about here?

What does it matter? FYI it's a 1999 328i (E46).

The above statement indicates there's no use in discussing this with you further. If you can't make your argument with doubting the existence of my mechanic (because independent BMW mechanics are so rare as to call into question the truthfulness of anyone stating they have one) then there's nothing more to say.

Bolt Drain and Fill at 5 Qts - $60 on ride requiring Esso LT71141.
I just did another bolt and fill 2 weekends ago.
Pan Drop and Fill - IF memory serves me correct, it took around 8-9 qts.

Fluid ain't rocket science. Such a heated debate. DO what makes you comfortable. Just make sure you are putting in the correct fluids...

OT
I orbit out, and then back into this thread...
I think I am trapped back in Debate class, in HS. :rofl:
:thud:

Not positive, but pretty sure the e36's had a different ATF fluid interval. I was making sure you weren't calling on that model. Also, if your X has under 100,000 and you call a few dealers letting them know your car has under 100,000 but you want it changed anyway, I would not be surprised if some try to convince you that it was not due up yet.

That is disappointing because I am still waiting for you to explain to me how you equate "all too often" with "slight". :confused:

Once again, you have failed miserably to provide us with any proof regarding your theory, the existence of your omnipotent indy mechanic or that you actually made phone calls about your e46 to any dealers. I will now bid you adieu with something a very confused forum poster once said, "I will remind you the person making a claim has the burden of proof". :D

Hey guys....I like pie. :)

I HATE PIE! :zoom:

And here's the link that proves I'm right!

I Hate Pie!

How about rainbows, muffins, cupcakes or guns?

This subject is like debating which is better, democrat or republican...do whatever makes you feel better. I'm just trying to lighten the mood.

I hear ya'

I find these type of "which oil is best, how often should I change oil, etc" discussions to usually be interesting at first, when some data, facts, or additional views and information are posted. But inevitably, once the facts and other info runs out, they sorta lose their usefulness.

Not that I'm not guilty of similar behavior at times....

While I agree with do whatever makes you feel better I don't agree this falls along the lines of which is better. Which is better is subjective. Whether changing the ATF results in subsequent failure of the transmission is not. Either there's a correlation or there is not. And so far no correlation has been proven.

Correct.

And so far no correlation between not changing ATF and shorter transmission life has been "proven" either.

When it comes to maintenance actions, very few have actually been "proven." "Proof" is often hard to come by. I know someone who did their very first oil change on a Toyota Corolla at 25,000, which had the factory fill of non-synthetic oil, 25 years ago. Their engine was still going strong at 100,000 miles when they sold it. But that's not proof and I still think I'll change my oil more often than that and pay for synthetic oil.

So again, it's a judgment call, and people have to make it on the information they feel is important and/or the "experts" they trust.

I myself believe in changing the AFT; however, I can see the argument for not changing it, and I am open to the distinct possibility than I am wrong.

If anyone ever comes-up with some hard data that is statistically significant, I'll be very interested.

And this is why I say "Do whatever makes you feel better" instead of "You have to do it".

I actually read through almost all of this thread.

This is a really good thread, in that, anyone who doesn't have a firm opinion on whether they should or should not change their transmission fluid (especially at a high mileage), ... who ends up finding this thread through a search and reads through this thread.... will most definitely NOT change the transmission fluid, based on the materials presented by both sides AND the manner in which they were presented.

Then they would being doing so against sound advice and favoring an urban legend.

Well, I probably should just drop this, but why is that any more of an "Urban Legend" than the "Urban Legend" that changing your AFT will make your transmission last longer?

I guess I am saying that the term "Urban Legend" is a bit strong and misleading in that context. I would position it more as "debatable and supported only through anecdotal reports, which are not statistically significant."

Which could also be said of the other side of the argument.

P.S. I promise to shut-up about this topic after this post. :D

When this post hits 1,000 I am going to personally call the Castrol dipstick guy to come to each of your homes and whip you on the back of the legs.

Arguments pro "change the ATF":

• BMW recommends it at 100K mile intervals.
• No fluid is lifetime. Lifetime being defined as never change.
• Fluids act as a detergent and become dirty with use.
• The protective qualities of lubricants breaks down over time.
• Every other fluid in the vehicle is subject to change at regular intervals.
• Other vehicle manufacturers recommend ATF changes.

Arguments con "change the ATF":

• In 2002 Mike Miller, head technical editor of BMWCCA, made the recommendation to avoid ATF changes due to his observed increase in subsequent transmission failures.
• Numerous web sites making the same recommendation as Mr. Miller.

So we have facts for pro "change the ATF" (I put this in quotes because my argument has never been to change the ATF but more it doesn't hurt to do it) and opinions on the con "change the ATF".

In 2009 Mr.Miller appears to have reevaluated his 2002 recommendation and no longer has the passion for it he once had (but does continue to say there is a risk). As for the numerous web sites I suspect they picked up on Mr. Millers 2002 recommendation and ran with it. And now discussions on this subject make references to one another (it happened in this one) in a form of circular support (I've seen this happen too many times).

Many disagree with my urban legend label but that's how I view it. An unsupported claim has been made and repeated ad infinitum and taken on a life of its own. So much so that people making it feel threatened when someone dare question it.

Comments included above in red.

I should clarify that I don't necessarily think that ATF should never be changed, or that it should always be changed. I do think that readers should make their minds up after understanding the risks and rewards. There is no conclusive data either way. There are reasons to change the fluid, and reasons not to. Readers making an informed decision after understanding the two sides is far better than blindly changing it because it is somehow supposed to be done.

My responses in blue.

It seems we've been agreement the entire time.

Yet the con "change ATF" people act as if there is. My position is, and always has been, there's no data to show a correlation between changing the ATF fluid and subsequent transmission failures. Therefore it's an urban legend, folklore, wives tale, what-have-you.

Others have noted that your continued use of the phrase 'urban legend' is somewhat misleading. I agree with this observation. It is an urban legend to you because you have never seen it, and are not familiar with the workings of an automatic transmission. If I have seen examples firsthand that persuade me that there is a risk that outweighs the rewards, and at the same time I don't even know who Mr. Miller is but rather rely on my own experiences, it doesn't feel like an urban legend. Anecdotal, perhaps. However, many things in life are based on professional judgement, as opposed to internet heresay.

MD was correct in that this is a little like a high school debate. The purpose of it to me, though, is to show both sides of the argument, so that future readers can make their own minds up and not rely on the old wives tale/urban legend/etc that all fluids are worn out soon after being installed. I think we are probably accomplishing that.

:iagree: As anyone can see from my first post in this thread where all I was trying to do was let people know there are possible risks. I personally think it is worth letting people know. Like I said, I didn't realize this myself until shortly after buying our X in 2007.

Simply put, I will be changing my fluid and filter at the same time I change the friction materials or other components in my transmission.

Regardless of whether you change the fluid every 100,000 60,000 or 3,000 miles the friction material on the plates will inevitably wear, as will the electronic solenoids/valves and the rubber components. The fluid does break down over time, but the nice expensive synthetic fluids used in modern transmissions like in BMWs lasts a really long time before losing its lubricating and hydrolic properties.

If the fluid was overheated by repeatedly towing heavy loads then it can lose it's viscosity and should be changed, or if you have a component fail that spreads metalic debris that suspends in the fluid and clogs the filter. Lots of times the metal particles are tiny enough to flow through the filter and stay suspended in the fluid which is bad for all other moving parts.

The reason transmissions can fail if the fluid is changed at a higher mileage is simply because the worn off friction material is tiny enough to flow through the filter and stays suspended in the filter, adding to the viscosity of the fluid which adds hydrolic pressure, as well as adding to the friction between the plates. When you change all that fluid with fresh new fluid the extra friction/grip in the plates is gone and replaced with fresh slick fluid as well as slightly lower hydrolic pressures pushing against the plates... which all adds up to cause slippage, thus transmission failure needing rebuilding.

There is no proof or solid documentation depicting this because each and every transmission will be an individual case of wear and other variables due to the use and driving styles of different people. If you are considering whether or not to change your transmission fluid I would strongly suggest taking a small sample of about half a pint or so to inspect. You can look at it stirring it under bright light to inspect for presence of worn metal components. (will look like metal flake in a paint job) Same for presence of clutch material. (dull gray material, like graphite powder) as well as smell the fluid to see if it smells like tranny fluid (kind of a gear oil smell in BMW's case with the lifetime fluid) or if it smells burnt from overheating/overworking.

Basically you should look at the fluid in each individual case and get as many facts as possible from the fluid in each particular case to get a better idea, and thus make a judgment call from knowledge, not blind beliefs.

my 0.2c over :D

This thread has really grown by leaps and bounds, fortunately however, buried within it is some really great information. One of the best posts, if not THE best IMHO, is #180 above by Weasel. I agree with basically everything he is saying, but at the same time I want to throw in a few of my own comments / observations into the mix.

1. BMW recommends 100,000 mile transmission fluid changes, not "lifetime" which actually is a recommendation for other other fluids such as coolant. (Now let's forget for a minute what is the motivation behind this recommendation) The caveat is that this recommendation applies to transmissions that were operated under "normal conditions." What constitutes "normal" I personally have no idea. Is it me driving a car or my grandmother? Further, in the case of a vehicle specifically designed to go off road, tow up to 6,000 lbs, and yet still perform like a sports car, I REALLY have no idea what is "normal!" In any case, the recommended fluid change interval is in fact different for an X5 driven in not-normal conditions (let's put it that way).

2. The multitude of problems that come with trying to define normal / not-normal situations are pretty obvious. So here's just one example. If you bought your car used, who knows how the previous person drove it? Maybe they pulled a trailer every day up until the point of sale? Maybe they thought they were Michael Schumacher (though not the current dude in F1)? Or maybe they drove to Bergdorf's every other day for shopping? All 3 of which I would consider not-normal, for differing reasons. Since you don't know for certain, perhaps an early fluid change is the way to go? And since you really DON'T know, perhaps an early fluid change at ANY mileage is the way to go?

3. In something I read, ZF seems to back point #2, however they state that looking at the fluid should be your guide. Last time I checked, my eyeball did not contain a microscope and built-in fluid analysis equipment to make an educated determination on fluid composition. Few people have JCL's experience in this stuff and so unless the fluid is burnt to a crisp, I don't know any one of us normal people who would know if indeed the fluid needed changing or not without some sort of detailed lab report to go by. Interestingly ZF recommends that the fluid be changed when it smells burned, however "the damage is already done." Nice one.

4. On their website, (see attached screen shot photo) they discuss their LifeGuard Fluid 6 (which is a special fluid blended by Shell for ZF; Shell calls it M1375.4; see photos) as offering extended maintenance intervals to 100,000 km / 62,000 miles. Interesting. This is certainly no 100,000 miles / 162,000 km recommendation. So if an EXTENDED maintenance interval on this fluid (which is after all the OE fluid and the ONLY fluid recommended for this gearbox) is 62,000 miles then perhaps driving in not-normal circumstances would warrant fluid changes at intervals shorter than 62,000 miles?

5. The transmission maintenance recommendations from ZF (see attached fluid recommendations and interval recommendations below) have some different information. Here they indicate that should not-normal (my words) conditions exist, maintenance intervals should be as low as 80,000 km (49,600 miles) or as high as 120,000 km (74,400 miles) or 8 years. So now what does this mean? If you don't have a clue how your transmission was treated should you have the fluid changed at 49,600 miles? How about if you have 25,000 miles and your car is 8 years old? Are they saying that the fluid is now sufficiently broken down to warrant changing?

6. In a letter from ZF circulated to shops (see attached) it discusses "lifetime fill" and leaves it up to the car manufacturers' to decide what that means, however it does address the notion of what I am calling not-normal conditions. In such conditions it calls for 100,000 km or 8 year fluid changes. Yet another different recommendation!

7. Given all the above, the way I understand the recommendations is that the best option is to have a fluid analysis done in order to determine whether or not a fluid change is necessary. A company like Blackstone Labs (no I don't work for them) might be the best option, see attached sample report (thanks to the original poster of it in a different thread).

I don't have any of the answers, just wanted to post some of what I had discovered on this clearly complicated matter.

Confused yet?

Meister, good background info.

A couple of comments to muddy the waters (fluid) further:

We keep discussing miles (or km) here when in fact that is not likely to be the best predictor of life. I have experience with heavy duty off highway transmissions in haul trucks and other applications. These trucks (up to 400 ton capacity) have a form of automatic transmission, and mechanical drive, not electric drive. As the trucks got larger, and when we got up to 2000+ hp (they are now up over 3500 hp) the impact of a failure was so extreme that the monitoring of components like transmissions got very precise.

We had traditionally measured component life by hours (since these are low speed applications, up to 60 km/hr). What emerged was that there was a better indicator than hours, or truck load, or grade, and that was the number of transmission shifts. It became a predictor for transmission component exchange intervals. On a long haul road out of a deep mine pit, the trucks would sometimes shift at every cross road, as the effective grade changed. That caused early transmission failure. It turned out that the grade didn't matter as much as the consistency of the grade.

We would have fleets of 20-50 trucks, at each of 10-20 minesites, and so could produce good analytic data (which we can't really do with over the road vehicles, where we have anecdotal reporting at best).

The point of all this is that just like with heavy equipment, the number of transmission shifts is likely to be an indicator of failure. Driving on the highway in 5th or 6th for 100,000 miles is nothing like driving in city traffic for 100,000 miles, and I think that this multiplier is far more than it would be for trailer towing, or spirited driving, which you mention.

Second point is about fluid sampling. I am a big fan of fluid analysis, have worked in a fluid analysis lab, and used it for years. The company I worked for had a very large lab (not Blackstone) That said, it has limited value when applied to cars. That is simply because the value is in trending the results, preferably with a fleet. Point samples are virtually useless. Many car owners do one, or two samples, and use it to justify what they already believe to be true. Other vehicles can't be compared to theirs, due to different duty cycles, driving conditions, fluids, etc. An oil sample can find water, or antifreeze, and that is valuable. It can measure TBN, which if trended can show additive life. It can measure viscosity, but you need to know what the acceptable viscosity is to make that valuable. Unfortunately, what usually happens with oil samples is that people focus on the metals found through spectrometry, which are dissolved in any case. Those results are telling you about your engine (or transmission), not about your oil, in most cases, unless you are paying additionally for large particle analysis with your oil sample.

Edit: I just had a look at the attached sample, and I think that it supports this. There is no detailed information on the results expected for the specific transmission (they don't even note who made the transmission, so how could they?) The universal averages are for an indeterminate population. The viscosity is (surprise) within spec for both measures, yet there is a recommendation to change the fluid based on elements found in the fluid that may have been there since break in. I wonder if that copper came from the clutch plates, or if there is perhaps a cooler in this system that could have provided the copper over the last 83,000 miles? And then with all that inconclusive data, the interpreter advises to change the transmission fluid after 10,000 -15,000 miles. That doesn't seem to be a supported recommendation based on the sample results as reported. This just shows the cautions needed when using fluid analysis, which is in general good science.

Excellent points, and particularly interesting real world examples I must say.

I agree with your thoughts on fluid analysis and that, just like in virtually every science, multiple data points are preferred if one is to make any educated guess on the future based on prior results. I think what Blackstone is in reality saying in their assessment is that they need more data points to see what is really going on. And much like you said, an analysis at another relatively short mileage would help answer (somewhat at least) the question as to when some of the particulates are appearing in the fluid; at break in a long time ago or relatively recently.

What I do find interesting is that ZF seems to be implying that since modern fluids are quite stable and have the ability to hold particles in suspension for longer periods of time, that failures caused by fluid changes shouldn't happen... at least up to a point. The question is just what is that point... 80,000km, 100,000km, 120,000km, 100,000 miles or 8 years?

Your heavy equipment example got me thinking. What would be an interesting thing to look at is what other car manufacturers that use the same transmission and fluid recommend. It won't be a perfect comparison, because those manufacturers (Audi, Bentley, Hyundai, Land Rover, Jaguar, Maserati, etc) will all have different software to operate the transmissions differently from BMW, however what would be fascinating to know is what Maserati, for example, thinks in terms of fluid change intervals on a ZF 6HP26 transmission used under their definition of "normal" conditions in a sports car versus Jaguar who might use it in a luxury saloon, versus Land Rover who uses it in a true SUV, versus Hyundai who uses it in their whatever mobiles?

I'd like to chime in on my recent drain interval on such a hotly debate. YMMV, and I would think twice about changing fluid if you are in the higher mielage and do not know the previous mechanical history

At 75K, this would probably be my 3rd fluid change - maybe even 4th. Too lazy to look at my records...Fluid is CHEAP to me. I have done 1 drain bolt as well as a a pan drop. At 75K, I just did another drain bolt. I was having some weird noticeable slight lag issues upshifts to 3rd gear. It's not a placebo effect but refreshed fluid did make that go all go away FWIW.

Now that being your 3rd change by the 75k mile mark will keep you from having the bad side affects of waiting till a higher mileage like 100k for the first fluid change.