How many here have owners manual with contradicitionary information on AT service

[Gurjit]

zf says its not lifetime, they built the tranny/designed/tested it

bmw says lifetime, they shoved it in their car

who do you believe

[TiAgX5]

Originally Posted by Gurjit

....bmw says lifetime, they shoved it in their car.....

and get a significant portion of trans swaps post failure. The service dept keeps the showroom lights on.

[bcredliner]

Originally Posted by trader4

If BMW defines the lifetime of their cars as 100K miles, they should put that in the sales literature. It should do wonders for their sales. You would think BMW would define exactly what "lifetime" means, but if they have, I haven't seen it anywhere. And it's certainly an important thing that should be clearly spelled out.

As we all know a BMW service mgr. does not speak for BMW. Undefined, lifetime means you never need to change it. In the handy dandy Bentley version of the BMW service manual, lifetime is defined as--No oil change is required for the entire service life of these transmissions. It also says if repairs have to be made to the transmission or transmission oil cooler, use only the recommended lifetime fluid to refill. Under troubleshooting a transmission--Minor automatic transmission problems may be corrected by changing the automatic transmission fluid (ATF) and filter. It goes on to explain how to diagnose the problem which would identify if a fluid change is needed. There is nothing that even implies don't ever change the fluid if the transmission is working fine.

So, if the transmission is working fine you can leave it alone if you choose. If the transmission is not working right changing the fluid might fix it. If you want to change the fluid just because you think it is a good idea it is not a Bozo no-no.

[JCL]

If you think the fluid is good for 100,000 miles and that is lifetime, then go ahead. Transmission lifetime isn't defined in miles. It is defined in lifetimes. All that means is that the fluid is good for as long as the transmission goes, and that that transmission lifetime mileage isn't impacted positively by early fluid changes.

[TiAgX5]

ZF position on fluid change (upallnight provided link in another fluid swap thread).

ZF 5HP Transmission Oil Change Interval Procedure - YouTube

[Doru]

The transmission is not built by the car manufacturer. therefore, one should look up what the transmission manufacturer recommends. BMW has no say in this, owner's manual, or service manual.
If one has a ZF transmission, then you should follow ZF service interval, which is 100,000Km to 120,000Km Max. Check this post where a forum member from Europe serviced his transmission at a ZF facility - post #11. Also detailed info what the service actually is.

This should close the debate. BMW has NO say in this, they didn't build the tranny, they just installed it in the car.
But in the end it's your car, and if your pipe dream about "lifetime fluid" fulfills your needs, than don't change the fluid.

[TiAgX5]

I agree with Doru.

I'm not trying to convice anyone who believes in lifetime fluid to swap it.

Just posting the manufacturers recommendation.

[bcredliner]

Originally Posted by JCL

If you think the fluid is good for 100,000 miles and that is lifetime, then go ahead. Transmission lifetime isn't defined in miles. It is defined in lifetimes. All that means is that the fluid is good for as long as the transmission goes, and that that transmission lifetime mileage isn't impacted positively by early fluid changes.

[bcredliner]

Originally Posted by Doru

The transmission is not built by the car manufacturer. therefore, one should look up what the transmission manufacturer recommends. BMW has no say in this, owner's manual, or service manual.
If one has a ZF transmission, then you should follow ZF service interval, which is 100,000Km to 120,000Km Max. Check this post where a forum member from Europe serviced his transmission at a ZF facility - post #11. Also detailed info what the service actually is.

This should close the debate. BMW has NO say in this, they didn't build the tranny, they just installed it in the car.
But in the end it's your car, and if your pipe dream about "lifetime fluid" fulfills your needs, than don't change the fluid.

[bcredliner]

Originally Posted by trader4

Did you watch the ZF video from the provided link? In it ZF clearly says that:

A - You shoud adhere to the vehicle manufacturers specific instructions regarding fluid change interval (So, it's right back to BMW "lifetime")

B - That ZF fluids are designed to maintain their characteristics for lifetime, per the vehicle manufacturer's specifications.

And after that, ZF states that under extreme conditions, *then* the fluid should be changed every 50 -70K miles or 8 years.

See post #15