How do I remove rear wheel bearing 85 BMW 318i?

Answer 1

More than one Web site has a solution to removing the rear wheel bearing from E30 BMW. If your car is not rusty like the ones here in NY, you might find this easy.

Assuming you have the tools to start this job (jack, proper jack stands, 30mm deep socket, breaker bar, medium sized gear puller, etc.), you start by loosening the 30mm nut on the axle shaft end. I ground the end of a 30mm socket so that it goes past the lock plate and fully engages the nut. Turn the nut off with the car on the ground.

Block the front wheels securely and raise car and put on jack stands. Try to push car side to side and fore and aft. If it falls, count yourself lucky and try again.

Remove the wheel and drum or disc. If disc, must remove brake caliper first.

Remove the six Allen socket head screws at the differential flange. Lower the axle end so it misses the differential. Hang it in place with whatever.

Using gear puller, push stub axle through bearing. If you feel that you have to hammer it through, realize that you could damage the threads at the end of the axle and ruin your chances for recovering your core charge.

Once axle is out, go around to the inside of the backing plate and hammer the flange out of the bearing using a healthy-sized hammer and a thick steel rod or punch, or a piece of galvanized pipe, about 3/4 in. size. This will probably cause the bearing to come apart. It is worn out, after all, and is less likely to stand the hammering.

Clear all the bearing pieces out of the hub, except of course, the stuck-in or rusted-in outer race.

Now, either buy the bearing removal tool from bavauto.com for $250, or a Lincoln Electric AC Stick Welder for about the same price from Sears. Welding electrodes, helmet, etc. would be a little extra. If you choose the welder, now you can also weld your granma's bedstead back together which you'd never be able to do with the POS tool from bavauto.

You might have to hunt for a place to plug in your 240VAC welder. You can try behind your kitchen electric range, or behind your dryer. You might want to wait until mom is away.

If you use the welder method, remove the large circlip that retains the bearing, then heat the outer race in the hub until it's thoroughly red hot in one place by depositing a bunch of weld metal in the middle of the race and moving slowly around the race for a maximum of 2 inches or so. Don't bother going near the edge of the bearing race with the heat. It is not necessary. The race is rather thin there and the thin part does not exert much resistance to removing the race. You don't want to weld the race to the hub by mistake by melting through the thin metal.

(Someone might prefer oxy-acetylene heat. If you'd rather, go for it.)

Go around behind the backing plate and tap out the outer race with your drift and hammer. Clean up the hub, and you're ready for reassembly.

If you have a MAPP gas torch, you might get lucky by heating the hub 'til it smokes and pushing and tapping in (using the old bearing race as a driver) the new bearing coated with a graphite-heavy anti-seize compound, but don't count on it. It's better to make a bearing installer out of a piece of 1-inch allthread, some pieces for steel to make a bridge for your installer (Google adjustable bridge puller, or look on eBay for bridge puller to see what the bridge is), 3 or 4 1-inch nuts, and a selection of very large thick washers (up to 3 in. O.D. from the hardware store, at least two of each). You will need a couple of pieces of steel for the legs of the installer too. Two equal-length 3/4 in. pipe nipples would probably work, if their ends are squared off. The legs push the new bearing outer race (don't push anywhere else on the bearing), using the old race to actually push on the new bearing.

The bridge material can be purchased at a steel supply, or a machine shop. (they might just sell it to you to get rid of you). A piece of rectangular tubing about 1 1/2 in. by 3 in., 5 in. long with a 1-in. clearance hole drilled through it in the middle, through the narrow side should work. Should be about 3/16 wall, or thicker. I think I actually used the flange for a bridge. Anyway, the installer is set up by having the allthread with one end through the hub with washers larger than the hole in the backing plate on the differential side and with a nut to push on the washers, and a nut on the other end to push on the bridge, which pushes on the legs, which push on the old race, which pushes on the new bearing.

It can be a rather hard push, so lube up your threads with oil and anti-seize compound.

After the bearing is in, reinstall the retaining ring. Use your installer to push the flange into the bearing. But first, be sure the axle splines slip more or less easily into the flange splines. If they don't, find out why and fix it. Look for dirt in the splines, or burrs that need to be filed or otherwise removed. I didn't do this and had to have a machine shop turn down one of the axle nuts and weld it onto a piece of tubing and weld a 1-in. nut on the other end. Then I could suck the axle through the flange using the installer.

The rest of it is the expected reverse order thing. I don't bother with those dumb lock plates. I use a torque wrench and just over-torque it a bit and dare it to come apart. I don't lube the axle or nut threads.

Enjoy.

I hope I didn't forget anything.