gear oil for x5
 

hi, guys
i have 02 x5 4.4 with sport pkg., and i am going to change gear oil. do all x5 have limited differential?
thanks,
james,

All I used is Redline 75W-90 gear oil. Worked for me. 2 quarts did the job.

No X5 models have limited slip differentials, they are regular open differentials. No reason for special gear lube.

I can say the BMW OE fluid is an expensive synthetic fluid, but if you plan on servicing the fluid at a normal basis as with other vehicles you should be fine with normal gear lube. The Redline 75W90 mentioned above by CharlieHustle is a synthetic lube as well and a fraction the price of BMW's lube... Should be perfectly fine.

I read somewhere that a member used something without an additive and cooked his diff. Is the BMW fluid castrol?

I haven't seen that post. I have seen a post whereby a member put ATF in his x-drive transfer case (post 2004) with bad results. I have also seen a post whereby a member put non-gear oil in his differential with bad results.

I have been using RP 75w90 for about 50k.

I'm curious too, what is the BMW fluid?

If I'm not mistaken it is a synthetic gear oil made by castrol. Maybe I can write down some specs/part numbers etc off the label at work tomorrow. (only if my short term memory works ;))

Castrol SAF-XO 75W-90 makes reference to being designed for BMW and to BMW approvals for all non-limited slip BMW differentials in their literature. Seems likely that that is it.