Has anyone done a Transmission filter and fluid change and caused more issues?

[ants_oz]

While not disputing some of the claims made here, I do find it interesting (some might say amusing) that other complex hydraulic mechanisms (in such things as excavators, hydrostatic drive units) have no such claims to "lifetime fluid". Our excavators - we would NEVER dream of running the hydraulic drive oil for more than a few hundred hours at most. Our large mowers - same thing. The hydraulic fluid is lifeblood to these machines, and we're not talking a few grand worth of transmission - we're talking tens of thousands of dollars worth of repairs if you have a hydraulic issue that contaminates the system.

I suppose though, since the X5 really is aimed at the general consumer market, they (BMW) can make the assumption that for the vast majority of purchasers there will never be an issue in the "lifetime" (ie economical repair life) of the vehicle, so the claim can be argued as valid.

[srmmmm]

Originally Posted by ants_oz

While not disputing some of the claims made here, I do find it interesting (some might say amusing) that other complex hydraulic mechanisms (in such things as excavators, hydrostatic drive units) have no such claims to "lifetime fluid". Our excavators - we would NEVER dream of running the hydraulic drive oil for more than a few hundred hours at most. Our large mowers - same thing. The hydraulic fluid is lifeblood to these machines, and we're not talking a few grand worth of transmission - we're talking tens of thousands of dollars worth of repairs if you have a hydraulic issue that contaminates the system.

Number one enemy of hydraulic fluid is heat, number two is dirt. Heavy equipment is far more likely to encounter those issues than a vehicle transmission with a small vent tube. Likewise, operating pressures of those systems are typically much higher than in a transmission, so any contaminants would be more likely to damage seals and sliding surfaces... which is why I do however, regularly change power steering fluid.

If I had arranged for shop performed flush & fills every 50,000 miles on my transmission as some other members do, I probably would have spent between $2000 and $2500 on that maintenance by now, and still have a unit with 274,000 miles of wear on it. Depending on whether or not it ever fails, a re-manufactured unit with a 3 year warranty and all new wear components can be installed for about $3000. I just think that's the more cost effective and less time consuming way to go. I guess we'll see as I continue to rack up 500 miles per week!

2002 X5 3.0 274,040 miles
2004 325i 118,500 miles

[JCL]

Originally Posted by ants_oz

While not disputing some of the claims made here, I do find it interesting (some might say amusing) that other complex hydraulic mechanisms (in such things as excavators, hydrostatic drive units) have no such claims to "lifetime fluid". Our excavators - we would NEVER dream of running the hydraulic drive oil for more than a few hundred hours at most. Our large mowers - same thing. The hydraulic fluid is lifeblood to these machines, and we're not talking a few grand worth of transmission - we're talking tens of thousands of dollars worth of repairs if you have a hydraulic issue that contaminates the system.

I suppose though, since the X5 really is aimed at the general consumer market, they (BMW) can make the assumption that for the vast majority of purchasers there will never be an issue in the "lifetime" (ie economical repair life) of the vehicle, so the claim can be argued as valid.

My career background was in heavy equipment service (yellow machines from Peoria). I think there is a fair bit of difference between an automotive transmission and a hydraulic circuit on a tracked excavator, for example. We used to look for metal particles by connecting up particle counters on the return lines, and extending/retracting boom and stick cylinders, till we found the spike. The metal came from the cylinders fairly often. Not a failure mode that transmissions see. We don't see metal particles, we see burnt fluid from overheating, when that does happen.

It is an economic, life cycle cost calculation, at the end of the day. And that refers to the transmission life. I believe that the transmission will more likely fail from some other cause, whether electronic sensor or wiring harness or whatever, before it fails due to fluid degradation. Not always, but frequently enough that replacing fluid is a questionable economic investment. If the fluid was overheated due to some other problem, sure. But now that we have lock up torque converters, and ECMs that back off the power during shifts, and have sufficient transmission cooling to tow 7700 lbs on 12% grades without additional coolers, the transmission is pretty much set. BMW is even warming the trans fluid on a cold start to reduce wear. None of these things existed in the days of 3 speed slush boxes that burnt their fluid every 30,000 miles.

There is lots of discussion on the risks of failure post-fluid-change. I contend that it is a real risk, albeit a relatively small one. It is just that I don't see the upside, the statistics on how replacing fluid has extended transmission life. No data whatsoever. But we do get reports of failures, apart from those where the wrong fluid or filter was used, or where there was already a problem. In the past decade, maintenance planning has moved into the science category, while some are still doing things and spending money just because they feel good. I'm all for feeling good, and if it feels good do it, but don't pretend that it is going to extend the transmission life unless there is some rationale other than "that's the way we always did it".

Fun topic. Even with sunny, who is still singing about old wives and urban myths. Same as last time around.

[sunny5280]

Originally Posted by JCL

There is lots of discussion on the risks of failure post-fluid-change. I contend that it is a real risk, albeit a relatively small one. It is just that I don't see the upside, the statistics on how replacing fluid has extended transmission life. No data whatsoever. But we do get reports of failures, apart from those where the wrong fluid or filter was used, or where there was already a problem. In the past decade, maintenance planning has moved into the science category, while some are still doing things and spending money just because they feel good. I'm all for feeling good, and if it feels good do it, but don't pretend that it is going to extend the transmission life unless there is some rationale other than "that's the way we always did it".

Likewise there are no statistics to demonstrate replacing the fluid increases the risk of transmission failure. No data whatsoever. Just anecdotes.

Originally Posted by JCL

Fun topic. Even with sunny, who is still singing about old wives and urban myths. Same as last time around.

I'm happy to reconsider my position once you provide supporting data. Until then why would you think my position this is a wives tale would change?

[E53inLA]

Well, where do people stand on changing other fluids? Transfer case & final drive for example?

I did the transfer case shortly after replacing the actuator, and final drive is next up.

[JCL]

Originally Posted by E53inLA

Well, where do people stand on changing other fluids? Transfer case & final drive for example?

I did the transfer case shortly after replacing the actuator, and final drive is next up.

Personally?

Oil change prior to what the service lights call for, but usually by about 10% or so (last four vehicles). That means 24,000 km oil changes, including with the 535 twin turbo. Worked well.

Diffs if they get water in them (look for colour when checking levels).

Transfer case (x drive in my case) when the wear limits are reached (error code)

[E53inLA]

Originally Posted by JCL

Personally?

Oil change prior to what the service lights call for, but usually by about 10% or so (last four vehicles). That means 24,000 km oil changes, including with the 535 twin turbo. Worked well.

Diffs if they get water in them (look for colour when checking levels).

Transfer case (x drive in my case) when the wear limits are reached (error code)

Water in the diffs? Maybe in Vancouver.... but in Los Angeles?
The fluid guide I downloaded from XOutpost in 2010 suggests every 30K miles.

[JCL]

Originally Posted by E53inLA

Water in the diffs? Maybe in Vancouver.... but in Los Angeles?
The fluid guide I downloaded from XOutpost in 2010 suggests every 30K miles.

Water in the diffs from water coming in the vents when fording creeks. Applies to all makes, and all locales (except during droughts......)

Edit: there isn't a downside to changing the differential fluid and the pre-xdrive fluid earlier, except cost. 30,000 seems early, but what does the service guide say for your model? if you have xdrive, be aware of the fluid monitoring the transfer case is doing and any resets that may be required.

[E53inLA]

Originally Posted by JCL

Water in the diffs from water coming in the vents when fording creeks. Applies to all makes, and all locales (except during droughts......)

Fording creeks??? Is that a euphemism for car wash?

I suppose during a flash flood we might actually drive through a deep puddle when a storm drain get blocked.

Joking aside, I'm not very impressed by the systems that are supposed to warn service is needed. We've had brake problems and the brake sensor didn't trigger. The type of stop & go traffic, couple with hilly terrain make me a firm believer in changing oil more often than 15K.

But what I was really driving at is why trans fluid is lifetime, but none of the other gear fluids?

[SMOKEY53]

Originally Posted by JCL

My career background was in heavy equipment service (yellow machines from Peoria).

I work for the same people, although I'm in marketing (ie the colouring book and crayons department).

Nowadays all fluids compartments on the machine are put through SOS testing (oil analysis). Not sure if there would be enough similarity between automotive transmissions and machinery transmissions to warrant testing, but I could get the lab to run a sample on the fluid that comes out of my transmission (when I flush it) to see what's in there? I've got 115k's on mine.