Transfer Case and Differential

[carbob]

I'm doing some yearly maintenance on my e53 with 93k on the clock, last year did the transmission fluid change and spark plugs, obviously I want to keep this vehicle running well as long as I can. Should I prophylactically change the transfer case and differential fluids at this time? I know they are lifetime fluids, but that's not how I have been addressing any of my vehicles.

Thanks for the input.

[Ricky Bobby]

I did my transfer case and diff fluids at 65k shortly after I bought the X - I dont like relying on lifetime fluids

[lo_jack]

Yes, I would change them. BMW walked back that ridiculous lifetime fill garbage carefully without inducing a massive recall or class action.

I changed all fluids 80k miles ago at around 100k.
They are all easy to do with a fluid transfer pump of some kind. Make sure you have the giant hex sockets the diffs take beforehand, and make sure you can open the fills BEFORE you drain them.

I believe the diffs are 75w90 and the transfer case is something thinner like ATF, but don't quote me.

[Ricky Bobby]

^^This is correct pre-facelift Transfer Case is ATF - the diffs are 75w-90 - facelift Transfer case takes the BMW "magic juice" with the additive for the clutch packs

[bcredliner]

Yes, and use BMW OE or OEM fluids.