Originally Posted by
oldskewel 
If "diff oil" means the oil to put in your differentials, one of the most important things to be sure of is that it is GL-5 (and not GL-4, which would more commonly be used in a manual transmission).
I agree with oldskewel for the front and rear hypoid differentials.
Quote:
Originally Posted by jbfrancis3
... For the NV transfer case [non X-Drive], Dexron III ATF is the spec while D4 ATF is a common and accepted replacement, often providing GL-4 level.
|
I also agree with jbfrancis3 for the transfer cases, which may include a non-hypoid center differential.
I guess we should clear up some confusion. When I was seaching for transfer case info, I found as much info calling it a "front diff" which is clearly wrong. If any type of diff, a non-locked transfer case may include a center differential, but non-hypoid (so non-EP).
Our front and rear differentials definitely require a GL-5 EP (Extreme Pressure) lube. The requirements for the X-Drive ATC transfer cases were where the lack of info was, and it looks like for at least the E53 (ATC 500) and E70 (ATC 700), those take some sort of GL-4, perhaps with special non-EP additives. I imagine the EP additives in a GL-5 might be very bad news for these transfer cases.
Bottom line: GL-5 for front and rear diffs, some type of GL-4 for the X-Drive transfer cases (at least ATC 400, ATC 500 and ATC 700 where TF-0870 was originally spec'd before DTF-1 may have evolved), and ATF for the NV transfer cases.