Cartmanizm

My car has done 124,000km (77,000 miles) so I thought I'd get my transmission fluid changed as I plan on keeping the car for a few more years to come (that and shifts aren't as smooth as they used to be). I emailed both a reputable indy and the dealership to get pricing on the ATF flush, new oil pan, etc. The indy quoted me AUD $795 however the dealership sent me the following email:

I'm surprised that the dealership would turn down a job so I'm trying to figure out what to do now. Is it better just to leave the transmission as it is?

yelcab2

Change it.

KyleB

Cart, I dont know where that highlighted section came from but that is the worst advice I have ever heard. It is literally the OPPOSITE of what ZF recommends. Never take any advice ever again from the person that told you that.

Change it, you're due per ZF service literature.

txag_530i

Read the last sentence on page one of the following document:

http://www.zf.com/media/media/docume...hselkit_EN.pdf

"Depending on the driving style, ZF therefore recommends a transmission oil change every 80 000 to 120 000 km, or after 8 years at the latest."

Don't listen to the dealership!

DavidF

+1...change the fluid. Use a suitable fluid such as Valvoline MaxLife or similar synthetic fluid. ZF's Lifeguard is a good fluid, but mainly because it is rated at higher temps than most other compatible fluids. Therefore, you should change non-Lifeguard fluids more often (due to heat breakdown).

More often than not, transmission failures are due to mechanical issues not related to the fluid age or type. I.e. clutch pack drum lip breakage, reverse piston failure, o-ring failure, etc.

For instance I rebuilt my 5hp24 due to clutch pack drum lip failure after 225,000 miles (E38). I was running non-ZF approved fluid since 100k miles. The fiber disks and steels were almost as good as new. Steels still showed original machining marks. Transmission internals were clean as should be expected (i.e. normal gray film on surfaces).

wrx5

Instead of listening an Indy or stealership, I decided to give a call to ZF. I was on the phone with ZF Australia, 10 minutes ago. I asked them the famous question "when we need to change ZF transmission oil for BMW cars"

The answer was "a BMW car with ZF transmission model 6HPxx doesn't need transmission oil change. Oil is life time. What dealer says is correct."

I told them about above article @txag_530i posted. He said, he is aware of it but it doesn't change the fact that ZF LifeGuard 6 is lifetime fluid and doesn't need to be replaced.

Sharing what I heard.....

KyleB

Misinformation occurs at all levels of most companies. Unbelievable.

txag, great post. This is what should be referenced if you have any questions on how to maintain your transmission.

DavidF

This is a debate that will never end. People should do what their research tells them to do. For me, "Lifetime" is a marketing ploy. I am in the change the fluid camp.

txag_530i

Here's the ZF document in case the link ever changes.

ZF service information 1-6.pdf

ZF service information 7-12.pdf

KyleB

+1, it is most definitely a marketing ploy.