Many people do not "subscribe" to the concept.

Changing it seems to be OK as long as it is done properly, with the correct fluid as a replacement, and getting the level correct.
It is also very important that absolutely no dirt or dust get in during the process.

That being said - most BMW service departments will try to persuade you to NOT change it due to bad experiences - slippage starting soon afterward.

The reason they went to this fluid was mostly for maintenance and environmental reasons. BMW found that most transmission failures were occurring after fluid changes due to improper procedures. The environmental aspect is the use of less oil.

Some people have reported finding their oil to be in "bad condition" when they changed it. I checked mine last month (140,000kms and 12 years)and it is darker than new but still very clean, etc. I am not changing.

If you do change do NOT use a flush process as that can cause any trapped dirt to move to where it will affect the operation. Because the torque converter holds about half the quantity you actually have to replace the fluid 3 times (with runs in between).

It is essential to use the correct fluid (see the label on the side of the transmission) - and if this is the Esso fluid then it is very expensive so the 3 change process will be costly.

Cheers
Jim Cash

• e39 transmission 'lifetime fluid' question - bw 2008-09-05 09:33:17 (263 views)
  • The 'question' asked a thousand times. - jimcash 2008-09-05 11:00:43 (288 views)
    • Do a search on e38 board. LOTS of discussion for ages over there. (nt) - Roy In GA 2008-09-08 17:22:05 (120 views)