Transfer case fluid: ATF or?

[John Galt]

I'm planning on changing the fluid in the front and rear diffs and the transfer case this weekend. On the fluid for the transfer case, some posts say that it needs the same fluid as the transmission, and other posts say to use something like Mobil 1 Dex III ATF.

Tranny fluid: http://www.xoutpost.com/86008-post12.html

Dex III ATF: http://www.xoutpost.com/x5-e53-forum/...id-change.html

What is the right answer for the transfer case?

For the front and rear diff, can I just go with Mobil 1 75w-90? Do I need an additive?

Does the transfer case or front or rear diff have magnetic drain plugs? If not, does anyone know where I can get them?

[Zulu95]

I had all those fluids changed last year. Diffs got Amsoil synth gear oils and the T'Case got Amsoil synth Dex III.

[bjo]

For the diff I used Valvoline 80w-90 Semi-Synth..
Transfer case: Mobil 1 ATF.

[John Galt]

Originally Posted by John Galt

For the front and rear diff, can I just go with Mobil 1 75w-90? Do I need an additive?

I understand that the factory fill for the X5 diffs is Castrol SAF-XO 75W-90, which I understand from this site is an API GL-5 oil. Mobil 1 Synthetic Gear Lubricant LS 75W-90 is also GL-5, so this should be a good match.

I still would like to know if the factory calls for a friction modifier additive in the diffs, if these things have or can get magnetic drain plugs and what the story is on the transfer case.

Thanks!

[Zulu95]

If you check the Amsoil site they list it all for you.

[BobsX53.0i]

----------------------------------------------------------------------
Transfer Case -

BMW's spec for X5s without X-Drive is for ATF Dexron III (mix contents thoroughly before opening to distribute additives evenly)
---------------------------------------------------------------------
Front and Rear Diffs -For final drives without multiple-disc limited-slip differentials.
(Names of some approved hypoid oils)
BMW Synthetik OSP
AGIP HLX
Aral Getriebeöl BS
Castrol SAF-X0
Veedol SAF 66
Mobil Gearlube VS 600
BP Energear SHX
VALVOLINE HL Plus
TRANSELF BM 75W-90
Avia Hypoid 75W-90 EP

***General information about final-drive gear oils***

Final-drive and hypoid gear oil must fulfill the following requirements for
handling high stresses as arise at the tooth flanks of the hypoid gear:
-high load-carrying capacity
-good protection against scoring/scuffing
-good protection against wear
-optimum frictional behaviour and temperature stability
-compatibility with sealing materials
-resistance to ageing
A brand-name hypoid gear oil already possesses these and other characteristics thanks to its high concentration of EP agents (EP = Extreme Pressure).
Oil additives--All final drives are designed in such a way that there is absolutely no need to use oil additives.

[fast4d]

no friction modifier as the diffs are open and not limited slip

Originally Posted by John Galt

I understand that the factory fill for the X5 diffs is Castrol SAF-XO 75W-90, which I understand from this site is an API GL-5 oil. Mobil 1 Synthetic Gear Lubricant LS 75W-90 is also GL-5, so this should be a good match.

I still would like to know if the factory calls for a friction modifier additive in the diffs, if these things have or can get magnetic drain plugs and what the story is on the transfer case.

Thanks!

[dkl]

Originally Posted by BobsX53.0i

----------------------------------------------------------------------
Transfer Case -

BMW's spec for X5s without X-Drive is for ATF Dexron III (mix contents thoroughly before opening to distribute additives evenly)
---------------------------------------------------------------------

Any info for the xDrive equipped X?

[John Galt]

Originally Posted by fast4d

no friction modifier as the diffs are open and not limited slip

Excellent. Thanks!

[X5 in AK]

Just to clarify a bit, there WAS some info floating around that said to use the same oil in the transmission and the transfer case. This does not apply to the 5 spd tranny, which uses the Esso oil. The transfer case (non X-drive) is made by New Process and uses a Dex III fluid. You can use regular or synthetic Dex III in it. Most people that bother to change it opt for the synthetic Dex III by Mobil or Amsoil or whomever.