bimmerluuvr

My service advisor made me laugh today, I asked him to change the oil in my rear diff. today, he said he would have to check with the service manager first to give me an accurate price, he comes back and tells me that the drain plug in the diff. is positioned in such a way so as to render it unserviceable which is why bmw uses lifetime oil, he further says (and this is the really ridiculous part) that if I really want to change the oil, they would have to REMOVE the axle assembly to access the drain!!! I looked at him like he was crazy! needless to say, I took my car home (in a complete state of shock), jacked the car up myself, looked underneath, and BANG! there the damn drain plug is staring me in my face! Now this particular s.a. is the guy I deal with every time I bring my car in for something, we know each other, so WHY would he risk loosing a good customer by telling me something so stupid? and he is not the first to try to discourage me from having this service performed (just the first to do it in such dramatic fashion). Anyway, I want this job done so I bought a suction tool, plug socket, and I already have ramps and a floor jack, all I need is the oil and a replacement plug and o ring, how much more (or less) difficult is this (and the manual tranny. oil change) compared to an engine oil change?

bimmerluuvr

This is an OPEN post! ANYBODY AT ALL with knowledge and/or experience, and is welcome and encouraged to respond! come on bimmerheads, help me out here.

a2e60

If there is a drain plug and a fill/vent then there is nothing to stop you from going ahead. I have read that some diffs come with only one plug (as realoem would suggest) assuming thats the fill plug, you would have to remove the rear cover to drain. Your s.a. may have wanted to remove the entire diff to drain the oil rather than just removing the cover.

As a side note, a search of the forum shows capacity at 1.5qt.

Gareth

AlexFW

I can tell you that I know some days ago they put the new oil in my diff and it was on, not unmounted .

bimmerluuvr

AlexFW, could you run that by me again, sorry.

AlexFW

To replace the oil in your diff you don't need to remove the differential: I see they while are putting the new oil and the diff was on the car .

beaker

Even if there isn't a drain plug (not all of us have one), you can suction out the old oil through the fill hole.

Sounds like your SA just got some bad information. I wouldn't assume he meant to deceive you.

ukr

Make sure the car is leveled when you fill it.

What socket size did you get?

bimmerluuvr

I'll give him the benefit of the doubt.

bimmerluuvr

can't recall off the top of my head, but I purchased the plug sockets from Bavauto, they say those sizes will fit the drain plugs. I'll find out soon enough. Regarding the rear end, can I OVERFILL it accidentally?