OK I did transmission fluid flush on my 02 4.4i

[JCL]

Originally Posted by TwinTurboGTR

Ok, seems like we are getting no where. You've made your own claims that a fluid change WILL NOT cause damage to a transmission. And again thats fine. But if you are asking us to prove it, then you will have to as well. Otherwise, again, all heresay. So what I am asking is for your proof. Again, this is supposed to be a discussion and so far, its one sided.

But you'll probably come back and say "I don't need to provide proof" Well, thats fine. Our proof is from members that have explained the situation in detail. Also from techs explaining it in great detail (BMW techs and indy's). So sounds like this thread is dead. You want to provide YOUR proof, we welcome it. If not, then I guess your information is heresay, much like ours.

I probably shouldn't have waded back in again

I provided the links immediately above for the reading pleasure of newer members who might not have seen this particular debate before. It is all the same information as this time around.

I was also told last time around that the burden of proof was all on me with respect to the claim that properly done automatic transmission fluid changes on healthy transmissions can precipitate failures due to the detergent levels cleaning out the transmission, and shifting the resulting sediment into the valve body, causing shifting problems. My anecdotes, combined with the anecdotes of two forum members who were BMW technicians, and others in the business, didn't weigh up to the trusted independent that does Sunny's work. We couldn't help Sunny in this case, but there was a large offline discussion going on at the same time, just discussing that particular thread. It was, as my daughter would say, epic. It is the third one in my post above.

I also asked about a particular claim that Sunny made, namely that no fluid is lifetime and by inference, that old fluid was contributing to transmission failures. There was no proof provided for that claim. Using the same logic (one would think that would be logical, burden of proof and all....) I asked Sunny for his proof. He said it was a fact, he didn't need to prove it. That's in the third link as well, post #177. Oh well.

[e30cabrio]

I had an 01 Acura CLS. They had known bad 5ATs. Acura tried to blame it on everything form the lunar cycle to bad/corrupt fluids. My car had 182k when it left me and it's transmission never had a hiccup.

Bottom line fluids wear out. They reach an end of life and stop offering the protection for which they were designed. It seems counter productive to not replace potentially end of life fluid because it might cause issues from following a reasonable maintenance cycle.

I have always upon purchase of a new to me vehicle performed complete maintenance. I have no idea if/when the fluids were replaced, I got no records. I plan to do it anyway.

[TwinTurboGTR]

Haha, this is just becoming funny. I believe you said, and I quote, "I don't mean to be negative but it's my opinion there is a problem with the transmission that the fluid change has just covered. Ultimately the transmission will require repair and this will turn into another example of how changing the transmission fluid is a bad idea." (Sunny5280), and "Anyway this is rehashing a discussion I exited in the interest of keeping peace on the forum. I would request you refrain from engaging in posts which serve no propose other than to rehash the subject. (Sunny5280)"

Hmmm... so looks like this discussion happened before. Again you mentioned burden of proof, but still had none of your own?

It is probably safe to say we agree to disagree. You go ahead and change your fluids. That is fine. But for myself and a lot of other members, we will keep it where it is. Nothing for nothing, reading those posts... you kind of sound like you want to battle the tranny issue out. That's fine. But if anything, you are be irresponsible by saying a fluid change is good; as a fact, when you yourself have made no proof.

And reading those posts, there really wasn't any spin. JCL has made notes of other discussions from other members besides himself that are all in conjunction of what we've been saying. Again, you are entitled to your opinion. But I'm done with this thread. I've seen the previous posts mentioned and seeing you've had this discussion previously and you didn't come out looking so rosey then, yeah... I'm good.

Nice finds JCL. I liked the last one. Didn't read that one.

[sunny5280]

Originally Posted by TwinTurboGTR

Haha, this is just becoming funny. I believe you said, and I quote, "I don't mean to be negative but it's my opinion there is a problem with the transmission that the fluid change has just covered. Ultimately the transmission will require repair and this will turn into another example of how changing the transmission fluid is a bad idea." (Sunny5280), and "Anyway this is rehashing a discussion I exited in the interest of keeping peace on the forum. I would request you refrain from engaging in posts which serve no propose other than to rehash the subject. (Sunny5280)"

Hmmm... so looks like this discussion happened before. Again you mentioned burden of proof, but still had none of your own?

Again: I don't have to provide the burden of proof to disprove someone else's theory.

For example if I were to say: Every morning you kill a kitten you don't have to provide proof that you do not. It would be my burden to provide proof to support such a statement. You don't have to do a thing in order to disprove it. Same applies here.

Originally Posted by TwinTurboGTR

It is probably safe to say we agree to disagree. You go ahead and change your fluids. That is fine. But for myself and a lot of other members, we will keep it where it is. Nothing for nothing, reading those posts... you kind of sound like you want to battle the tranny issue out. That's fine. But if anything, you are be irresponsible by saying a fluid change is good; as a fact, when you yourself have made no proof.

Please don't put words in my mouth. I am merely saying I have seen no supporting data to demonstrate changing the transmission fluid results in increased transmission failures. This is not the same thing as saying it is a good thing. Please learn the difference.

Originally Posted by TwinTurboGTR

And reading those posts, there really wasn't any spin. JCL has made notes of other discussions from other members besides himself that are all in conjunction of what we've been saying. Again, you are entitled to your opinion. But I'm done with this thread. I've seen the previous posts mentioned and seeing you've had this discussion previously and you didn't come out looking so rosey then, yeah... I'm good.

I looked just fine to people who understand logic and do not succumb to the "group think" (i.e. consensus) mentality. Do you still think the world is flat?

Originally Posted by TwinTurboGTR

Nice finds JCL. I liked the last one. Didn't read that one.

Apparently that's not the only thing you're not reading.

[e30cabrio]

I am interested in the argument against replacing old fluids that no longer provide protection.

Can someone please explain how it is better to leave it in than possibly dislodge unknown contaminants that may or may not be in the system.

[JCL]

Originally Posted by e30cabrio

I am interested in the argument against replacing old fluids that no longer provide protection.

Can someone please explain how it is better to leave it in than possibly dislodge unknown contaminants that may or may not be in the system.

Sure. Transmission fluid is designed to last a long time. It is in a sealed system, so it doesn't get contaminated by things like engine oil does. It has additives that fight oxidation, and foaming. There are also friction modifiers. Over time those additives become depleted. The fluid does wear out over a long enough period of time. It doesn't stop lubricating, but it does lose some specific properties. Recall that lubrication is the lowest requirement of a transmission fluid. It is a very undemanding lubrication requirement. That is why it is a straight 10w oil. It is primarily a hydraulic fluid. The question is, does it wear out before the transmission expires of other, unrelated causes? Most failures we are seeing are related to things not related to lubrication (wiring harnesses, sensors, etc). Those failures won't be impacted by a fluid change. So, there is a big question as to whether changing the fluid will have any effect on average transmission life.

Now, what happens when a transmission wears (naturally) over time? There are sediments created by clutch plate material, generally non-metallic, and they sit in the pan on the dirty side of the filter. Not the clean side. They look bad, but they don't hurt anything. They are also distributed throughout the transmission. There, again, they usually don't hurt anything. Now put in new fluid. Very high detergent levels, by design, that is what makes it last so long. Those detergents clean out the transmission. Same reason we use ATF in an engine to clean out combustion deposits. What happens when those deposits are loosened? They go through the transmission. They end up in the valve body. If they make it to the pan, no problem. If they get stuck in the valve body, in a sensor, in an actuator, etc, they can cause an early transmission failure. It happens. Not always, but often enough to show up in the statistics.

So the debate is, is the risk of damage (lets call it x) greater than y (the benefit of clean fluid, which is generally a good thing). If you believe that clean fluid is such a benefit that it overshadows the risk of failure through introducing new fluid, then change it. If you acknowledge the risk (small on a total population basis, but real) and don't see a history of failures due to aged fluid then you would not change it, save the money, and put it aside for an eventual transmission rebuilt not caused by a fluid issue.

There isn't a right answer. The only error, IMO, is not acknowledging that there is some risk, and that there is no demonstrated benefit. This isn't to say that all preventative maintenance is bad. It is usually good. But where there isn't a correlation between PM activities and extended component life, then it is better and cheaper to run it to failure. That is counterintuitive to some.

Hope that helps.

[e30cabrio]

Thanks for taking the time to give me that info.

My transmission is fine currently. I guess I'll leave it alone for now and just do the rest of the fluids (already did the power steering).

[HPIA4v2]

Interesting, so the argument "don't flush trans fluid on hig mileage" argument really support "change the trann fluid more often, early" argument. Think about it...

[SlickGT1]

Same old story, another new person.

JCL, are you sure our transmissions are sealed? What about that vent tube that runs all the way to the engine bay.

Whatever.

I changed my fluid at 70K miles. Not flush, but drain and fill. I had crap stuck in my solenoids at 80k miles, so that put in about 10q of new oil.

My Lexus GS430 came with a card in the maintenance manual to drain and fill transmission every 30k miles. It is a very rare occurrence for the Lexus trans to fail, but the cases where it does fail, people were clueless about the regular oil refresh it required.

Will I keep changing the oil in my X5. Yes I will. Is it possible it will fail, yes it is. But, in my case, I am not afraid to try. I also use the proper oil, ZF6, and use a computer to monitor the fluid fill temperature.

Is my transmission acting better? Yes it is. But that could be since I "maintained" it with new solenoids, new fluid (times 3), new seals, and removed the crap that was blocking my solenoids since the beginning.

[JCL]

Originally Posted by SlickGT1

Same old story, another new person.

JCL, are you sure our transmissions are sealed? What about that vent tube that runs all the way to the engine bay.

Whatever.

I changed my fluid at 70K miles. Not flush, but drain and fill. I had crap stuck in my solenoids at 80k miles, so that put in about 10q of new oil.

My Lexus GS430 came with a card in the maintenance manual to drain and fill transmission every 30k miles. It is a very rare occurrence for the Lexus trans to fail, but the cases where it does fail, people were clueless about the regular oil refresh it required.

Will I keep changing the oil in my X5. Yes I will. Is it possible it will fail, yes it is. But, in my case, I am not afraid to try. I also use the proper oil, ZF6, and use a computer to monitor the fluid fill temperature.

Is my transmission acting better? Yes it is. But that could be since I "maintained" it with new solenoids, new fluid (times 3), new seals, and removed the crap that was blocking my solenoids since the beginning.

By sealed I meant that it is unlike an engine, which has multiple sources of potential contamination of the oil. It isn't pressurized, so no it isn't completely sealed. One of the reasons to remove the fill tube going up to the engine bay (on other vehicles, not sure if BMW followed the same logic) was because leaving the dipstick out allowed contaminants to enter.

There is a possibility (not proof, just a likelihood) that the contaminants in your solenoids got there because the new fluid with the high detergent level loosened them and they travelled through the transmission, becoming lodged where they caused some problem. That is the standard complication that shows up following a fluid change. It doesn't always happen, and it doesn't always cause a problem. But that is the recognized failure mode, regardless. It is great if you got away with just the solenoids. And if you have gone any reasonable time from the fluid change, then it isn't likely to happen later, failures usually happened closer to the fluid change time. In my experience. Which isn't proof, as Sunny will want clarified.