transmission life

[JCL]

Originally Posted by SlickGT1

100% agree. My indies, 3 owners, and a ton of shops, had 1 trans failure after oil change in the entire time of running shops. They said they knew that trans was going to die anyway. When they changed the fluid, car would not move at all. They put old fluid back in, and it drove to the trans shop.

They say that BMW lifetime fluid bullshit is bullshit. Same as start the car and drive right away. Remember, BMW has to make the car last to 100K. After that its profits for them again when you show up with whatever is busted.

So don't change $80 worth of oil, and save up $4k worth of transmission. Yea, that logic is brilliant. Or maybe $80 worth of oil, with get you to 150k miles, instead of the usual 100K. Think about it guys.

Several of us who have run shops, and seen many transmissions fail after a high mileage fluid change when no symptoms presented prior to the fluid change, would disagree with your position. Let's just agree to leave aside all the transmissions that already had problems, or had the wrong oil installed at a change, or had the job done incorrectly. Those problems can be corrected or avoided, and those samples aren't included in the failures I mention above, transmissions which were working fine.

That doesn't mean that changing the fluid will necessarily result in a failure. But it is statistically more likely than if you don't change the fluid that week.

Balance that against the cost of changing the fluid several times, just on the hope that your transmission will last longer. Without any evidence to support that theory. We don't even have evidence of fluid-related failures being a problem, yet the fluid is being changed anyway. So who has brilliant logic here?

If you would like to get into the downside of extended warm up periods at idle, happy to do so. Drive right away means wait 10 seconds for the idle to stabilize. Then drive. Every second of idling after that increases engine wear, and it is easy to do something about it. Just drive, which reduces the duration of the warm-up cycle. Not only will you save your engine, you will save money. Pretty hard to argue with that logic.

[JCL]

Originally Posted by TiAgX5

As I stated in post #11, changed OE fluid at 100k miles and now at over 150k miles including ks of miles subjecting the trans to 12k lbs of truck/trailer weight to pull around. These +50k miles have been on Castrol UltraSyn Multi Import ATF that meets the LT 71141 spec. If non-OE fluid+100K miles B4 fluid change=trans failure, I would certainly have not be able to reach 150k miles on my the trans in my X.

IMHO, Me thinks that some who've had a trans fail after switching to a non-OE ATF had some other trans issues that caused the failure.

Changing the fluid has obviously worked well for you. You are also getting good life out of your transmission. I don't think the towing plays a big factor, since we aren't seeing a lot of heat-related failures, but it is additional data.

The one comment I would make is that the Castrol Multi Fluid is not certified to the LT 71141 spec. Castrol even say that; they say that it is OK to use it, but that what it is certified to is Dexron III. That doesn't mean it is a bad fluid, it could be perfectly good. But selling a Dexron fluid and saying that "it will be fine, trust us" is not the same as certifying your fluid to the LT 71141 spec. Particularly when ZF shops have seen numerous failures of their transmissions when they are operated on Dexron fluid, and they attribute the failures to the incorrect fluid. I think that your experience is good input for owners wanting to make a decision on which fluid to use. But those owners should also know what fluids are designed to the LT spec, and which are not.

[SlickGT1]

Just saying. All my automatic cars, well even the manual cars, I have always changed the trans fluid. On automatics, always a drain and fill after the initial drain and filter. My lexus, was so "Lifetime Fluid", that you couldn't even change the damn filter without some serious surgery. And buying that filter was a nightmare. Every 30K I would drain and fill. Never had a hiccup with any of the "modern" transmissions. Yea the old 90s transmissions were a nightmare, especially the fords. Nothing helped them. Change fluid or not, they would still die.

And TiagX5 is a great example of transmission lasting with fluid change.

[TiAgX5]

Originally Posted by JCL

Changing the fluid has obviously worked well for you. You are also getting good life out of your transmission. I don't think the towing plays a big factor, since we aren't seeing a lot of heat-related failures, but it is additional data.

The one comment I would make is that the Castrol Multi Fluid is not certified to the LT 71141 spec. Castrol even say that; they say that it is OK to use it, but that what it is certified to is Dexron III. That doesn't mean it is a bad fluid, it could be perfectly good. But selling a Dexron fluid and saying that "it will be fine, trust us" is not the same as certifying your fluid to the LT 71141 spec. Particularly when ZF shops have seen numerous failures of their transmissions when they are operated on Dexron fluid, and they attribute the failures to the incorrect fluid. I think that your experience is good input for owners wanting to make a decision on which fluid to use. But those owners should also know what fluids are designed to the LT spec, and which are not.

When that statement is made by a manufacturer, it's the consumers responsibility to consider the source. The source here being Castrol, a major lubricant supplier to BMW AG. I chose to take Castrol at its word and have no regrets at all, especially with the fact that the fluid is about 1/3rd the cost of ZF fluid.

As for the ZF shops placing trans fail blame on ANY fluid other then their own when found in a ZF trans. Do you really think if they got my trans with over 150k and found around 95% Castrol Multi-Import Syn inside they would acknowledge the FACT that it has lasted LONGER then it would have with their three times the cost "lifetime" fill?

Manufacturer backed repair shops like NOTHING better then to find ANYTHING non OE/OEM to place the fail blame on, this relieves them of taking any responsibility for the failure without even taking the effort of dropping the trans pan.

[JCL]

I wasn't referring to shops owned by ZF, I was referring to shops that regularly do ZF overhauls. We could refer back to RRPhil, who has posted here regularly, if you don't believe my experience.

Originally Posted by RRPhil

That ‘inventory optimiser’ fluid claims to be suitable for the ZF 6HP26 (Shell M1375.4/Ford Mercon SP), the GM 5L40-E (BMW ETL-7045E, ETL-8072B) and the ZF 5HP24 (BMW LT71141).

Having seen the (disastrous) consequences of filling a 5HP24 with Dexron on a number of occasions, the correct fluids clearly use different friction modifier packs.

I’m 100% with JCL on this one.

Phil

See his post here: http://www.xoutpost.com/861674-post50.html

Castrol supplies engine oil to BMW, not transmission fluid. I wouldn't listen to the recommendation of their tire supplier, either if they said which transmission fluid to use.

If you don't like BMW prices, buy it from ZF for much less. Or buy it from Esso. Both sell certified oils with the correct friction modifiers.

[TiAgX5]

My point is, if you accept as fact that there are, to Quote RRPhil...."(disastrous) consequences of filling a 5HP24 with Dexron on a number of occasions, the correct fluids clearly use different friction modifier packs.", then ALL 5HP24 transmissions that are using it WILL fail prematurely. Please explain how I am over 150k miles (well beyond the "lifetime" BMW say the trans should last), with 50k miles of it on the Castrol LT 71141, with thousands of miles of severe duty (12k lb truck/trailer GVW).
The lack of the alleged "friction modifiers" should have wiped out my trans long ago, not allowed it to be operating fine at over 150k.

FWIW, I found the LT 71141 fluid compatability info in the Bentley manual and the Castrol Product Data PDF showing BMW LT 71141 on page 2 of the attached. It's not defined as a Dextron Fluid at all.

[rph74]

138k on our 01 4.4 all original fluid.

I had the fluid changed on my 98 540i 4.4 automatic at 165k, and the tranny failed at 168k. There were no previous problems before changing fluid. It could certainly be a coincidence, but after my personal experience, I'm with JCL. I'm saving that $$ towards a new tranny someday. At the end of the day, the best insurance is having money in the bank!

[Dking05]

These transmissions are all luck.. Heres my/family expirence on multiple cars

4HPXX (740i) - 155k-ish [Slow death, but lasted past 180k when it sold] F
4HPXX (540i) - 144k original fluid and still strong as ever
5HP24 (X5) - 125k then devloped infamous shudder and lockup problems still going @ 152K
5HP24 (540i) - TQ lock up problem (I kid you not, somehow water got into the trans and the parts developed rust) Rebuilt and runs amazing now.
5HP24? (Rover) - 77k I think, then randomly died the second day the new owner got it. (So they said) It ran perfectly long before owner sold it.
6HP26? (550i) - 84K running perfectly, but will change fluid soon for safety.

[JCL]

Originally Posted by TiAgX5

My point is, if you accept as fact that there are, to Quote RRPhil...."(disastrous) consequences of filling a 5HP24 with Dexron on a number of occasions, the correct fluids clearly use different friction modifier packs.", then ALL 5HP24 transmissions that are using it WILL fail prematurely. Please explain how I am over 150k miles (well beyond the "lifetime" BMW say the trans should last), with 50k miles of it on the Castrol LT 71141, with thousands of miles of severe duty (12k lb truck/trailer GVW).
The lack of the alleged "friction modifiers" should have wiped out my trans long ago, not allowed it to be operating fine at over 150k.

FWIW, I found the LT 71141 fluid compatability info in the Bentley manual and the Castrol Product Data PDF showing BMW LT 71141 on page 2 of the attached. It's not defined as a Dextron Fluid at all.

Frequent failures on the wrong fluid does not mean 100%. It means frequent. Just because one didn't fail doesn't mean that none will. Faulty logic.

Your own attachment defines that Castrol fluid as certified to Dexron III on page one. It lists many fluid specs on page two that it doesn't actually meet, but which it can be used as a substitute for, including the LT spec.

[TiAgX5]

Originally Posted by JCL

Frequent failures on the wrong fluid does not mean 100%. It means frequent. Just because one didn't fail doesn't mean that none will. Faulty logic.

Not necessarlly. When a 5HP24 subjected to extreme duty is still running strong on a fluid that some claim does not have the "friction modifiers" necessary to operate/survive.

The "faulty logic" statement could be made when a trans failure is blamed on the Castrol LT71141 without a through "root cause" teardown/inspection. That inspection would need to show internal issues that have NEVER BEEN SEEN BEFORE ON ANY ZF "lifetime" fluid filled trans teardown/inspection after failure.

I am well aware of "faulty logic", seeing that my job requirements include worldwide travel for the aerospace industry (military and commercial), in order to define the root cause of failures and implement appropiate corrective actions.