I was offered to buy the fluid from the dealer, they would sell it, but the price was a shocker at $41 per qt.

So I found this place. WIN.

ZF LifeGuard 6 - Case of 12 x 1L Container

You can buy the fluid here. Sure as hell beats dealer price of $41 per quart.

Castrol Import Car Formula meets the BMW Esso 71141 spec (read the back of the bottle), and it's carried by AutoZone, Advance Auto, Discount Auto, WalMart, ect. I have run it for over 46k miles with severe tow duty and no issues.

I have the ZF 6 speed. Does the Esso 71141 apply? I would get some cheap stuff for sure to drain the system a couple of times right away. Since I already have a case of ZF Life6, I would use that for the final fills.

Hmmm $194/case when all it is is DEX6 synthetic ATF. 12 qts of Mobil1 Which is Dex6 is $96. It's your money but it's the same stuff. I'm under the impression that BMW shops don't even use the ZF. When there are so many ATFs that are cheaper that meet or exceed the Esso spec. Castrol, Mobil1, Guess what? Pep Boys Brand dex6 meets the spec at like $6 a qt.

DEX6 is DEX6. I've had it in my transmission for 60,000 plus miles, lots of towing and hard miles.:dunno: why would you pay more? It's a GM trans.

Do not use the 71141!!! The spec for the 6spd ZF auto (Man ID ZF-6HP24, Trans ID GA6HP26Z) is Shell M-1375.4.

The only GM trans ever offered in the X was the autbox that came with the 3,0 L engine, this thread is discussing the ZF transmissions that were mated to the V8s.

Yea I figured that was wrong. OK, so which fluid meets the Shell M-1375.4

Go to any of the places I mentioned in thread #22 and read the backs of the ATF bottles/jugs.

Yea I pretty much figured as much. You don't think ZF 6 would be significantly better though?

When it comes to oils/lubes/fluids I am a firm believer that you ONLY use what meets the manufacturer spec.
When a manufacturer (like ZF), designs an assembly (like an automatic trans), they provide a list of all materials (metals, plastics, rubbers) that will be used in the building of the assembly), to a lubrication provider (Castrol,Mobile 1,LubroMoly,Esso,Shell,Febi,ect.). This is done because ALL lubrication base and additive products have certain materials that they are incompatable with (read, melt certain plastics, dry out certain rubber compounds, soften certain gear band friction materials). Info on surface area of bearings and clutch/drum assemblies is also given to the lube provider because, as friction area decreases (like when a manufacturer adds a 6th gear to a 5 speed box without increasing the internal size),the required lubricity level of the fluid increases.
When it comes to lubricants, some people think that the newest, latest, bestest fluid is better for THEIR vehicle while just the opposite is true. Put a 6sd autobox fluid in a 5spd box that has greater drum/band surface area and you will have excessive slippage and possibly material degradition!

FWIW. If you go to an indy shop and inquire about what type of fluid they use, and hear a response like "we put this new/latest, super-galacticy, slipperer then snake snot fluid in all the high-end cars that come thru here" type line, get in your car and get away from there, fast!!!!!!