TMQ

Has anyone changed the differential oil?

I'm actually planning to do it after 3 thousand miles, since I plan to keep the car for a while. I hear that it's considered by BMW a lifetime fill, but various people recommend changing at either 30K or 50K.

Thanks.

ukr

The new differential doesn't have a drain hole. You'll have to suck the fluid out through the fill hole or open up the back side housing. At which point you'll probably need to replace the gasket.

TMQ

I was actually told that there is a drain plug. UKR - what's your source of info?

ARH_0700XX

My 2007 had a drain and fill hole so I would think the LCI's have them as well (did they change the differential housings?) You can tell fairly easily even without jacking the car up by looking underneath from the back. TMQ, you're doing well by changing it out earlier rather than later. I did mine with Redline 75w90 at 3000mi and the oil that came out looked terrible.

TMQ

ARH - Thanks a lot! This is the first that I've seen someone doing it to the E60. I think I'd go with the same Redline oil.

Do you remember how much fluid you use to re-fill the rear differential?

By the way, indeed the E90s 3 series do not have a drain plug.

ARH_0700XX

I went back in my emails and checked the order, and I ordered 2 quarts. If I remember correctly it only took about 1.5 so you should be fine with 2 bottles.

ukr

My 2006 has no drain hole or non that I could see. I know '04 has a drain hole and it also has cooling fins but they changed the rear diff in later years. This is what mine looks like http://www.realoem.com/bmw/showparts.do?mo...hg=33&fg=10

Where was your drain plug?

TMQ

I will take a look; I looked an appointment at a local shop and we'll see where it drains.

ARH_0700XX

ukr, thanks for correcting me, I guess I was confusing my E60 with my previous car (G35) which had a drain hole. I looked at the pic I took of the underside and now I remember that the mechanic was carrying around a pump when I walked in, which he probably was using to suck out the oil.

This is what the diff looked like (it looks like the link ukr provided):

JPJ

Isn't the drain plug item #4 on the realoem exploded view: SCREW PLUG WITH O-RING? What I don't see is a vent/fill plug -- I'm remembering on my 330i that there were 2 plugs.

I was thinking I would change mine with Redline before driving schools this summer. After you change from the "lifetime" fluid you have to keep up a regular interval (I think 30K miles is probably good enough).