If you do just replace the center bearing, make sure you mark the driveshaft so the it goes back together at the same place. The drive shaft is balanced as a whole unit. Although I have yet to replace a driveshaft, although it will become a notch in my belt this summer, I would venture to guess that a rear diff swap is probably a little less involved. At least there is less to remove. The diff is right there, you can leave the exhaust in place. The trickiest part is the four bolts that hold the diff to the rear sub-frame. Believe it or not I use a BMW box wrench with one side 19mm and the other 17mm to get to those. It is very thin and is able to get between the body and diff. It is on the short side for the torque required. So I then put my 17mm transmission drain plug tool on my braker bar and put that into the 17mm side of the BMW box wrench. The set-up really works great. I have pulled quite a few diffs. I pulled mine a number of times. Once to swap out my rear sub-frame, once to swap ratios and go LSD, and a few times in junk yards. Just be sure you really tighten the allen bolts that hold the half-shafts to the diff. You don't want them coming loose on you. Be sure they are tight and check again in about a 100 miles afterwards. Jenny Morgon did a column on this once. Does the 533i have a small diff for the E28? The small E28 diff is the big diff on E30s If so it should be perfect for your eta E30! You just have to swap the output flanges and rear cover, but that is pretty easy.
Thank you for the info on the little tricks it takes. This should help out a lot, as I usually end up learning the hard way. It's forums like this that the info is invaluable when it comes to firts hand exxperiences, You don't always get that out of manuals. I didi find someone had step-by-step instructions and included progreesive photos as they swaped out a differential aand from what I've seen doesn't appear to be all that difficult. Anyway, I've pretty much decided to do it myself an dthe $$ saved on shop costs, I can add something else I most undoubtable will want to change. Thanks again, Bill
From waht i've read, the 533i offers the same size differential as e30 although As you mentioned, may have to swap the flanges. bill
I don't know much about the 533i. I do know the 528i has the small diff and the 535i has the large diff. The large diff from the 535i will not fit in an E30. Let us know how it works out.
Yes, definitely. You will need circlip pliers and maybe the use of a bearing knife to get the old bearing off. No. The driveshaft is much easier than the diff. You can leave the exhaust on for the driveshaft too. I almost never pull and exhaust system. On a lift I can remove the driveshaft in about 30-45 minutes Pretty far off. There are 3 diff case sizes. The E30 318 (and the E36318ti) got the small case, all the other E30/E28 (exc early 528e/533i up to 9/82)/later E24s (E28 based, not E12 based) that were not M and most of the E23 got the medium, and the M5/M6 and a few of the E23s got a large case diff. All medium case diffs will fit the E30 (with a quick output flange swap.) The up to 9/82 E28s got an oddball diff that doesn't fit anything else. Found that out the hard way once when we had some poor sap come in with a nearly lunched diff and we couldn't set him up with a new one because we didn't have one that fit. The parts catalog says that you can swap in the later ones, but only if you have the correct rear cover (533/633/733 from after 9/82) and we didn't have one. Make sure you don't get an early diff, they are useless. I have a 535i diff in my 327i
Thanks Paul. I was aware of the three sizes. I was trying to say E30 small and large and E28 small and large. The E30 large and E28 small being the same. I obviously was about as clear as mud. Small, Medium, and Large sounds better to me and much less confusing. Wow, I thought the 535i got the large diff. Thanks for keeping me straight.
Keeping you even more straight, you will not find a 533 diff from "the same year" of 1988. The 533 was only offered up to 1984. In most respects (like swapping diffs with an E30), it is essentially identical to the 535.
Ah I don't think I referenced the 533i to 1988. I know they stopped production early on. What I don't know, did the 535i replace the 533i? Was switch done at the same time for the 6 series and 7 series?
Yes. THe 3.5 replaced the 3.3 in the USA in 1985 MY for all 5/6/7. This came with updated injection and ABS
