BMW E30 Front Wheel Bearing Replacement

Front Wheel Bearing Replacement

Symptoms: constant rumbling/grinding noise, and in my case, loud heavy grinding noise when turning. For me it was the driver side bearing that was bad, and the noise during turning only appeared when turning left. In case you're wondering about the noise, let me just say that it is very loud and pretty much impossible to miss!

Thankfully, this is actually a pretty easy job. So let's start with parts needed:

Parts:
bearing/hub assembly (bearing is typically not sold by itself, but rather as one piece with the hub)
bearing front dust cap
bearing rear dust cap (you could skip this one if the old one is in good shape)
36mm standard thin walled socket (as opposed to the thick walled impact sockets)
puller (might be able to do the job without it, read on)
breaker bar and possibly extension pipe
brake disc dust shield (not a requirement by any means, but if yours is rusted out, this is a good time to replace it) 

Also, sorry for the low quality pics, a phone camera is all I had, but they should be good enough for reference

Begin by loosening the wheel lug nuts.
Next jack up the car and remove the wheel.

Remove the bearing dust cap. This can be a rather tedious procedure, try using a small flat screw driver or something else to pry it off. (The picture shown above has the caliper removed, but you don't need to do this now as you'll be putting the rim back on.. this is the only pic I had of the dust cap.)

Once removed, you will see the collar nut exposed. The next tricky/tedious bit is to undo the lock tab that's bent in on the collar nut. Some people use a small chisel to brake it off, I managed to bend it back with a small screwdriver and a a mallet.

Next spray the collar nut and bearing area with plenty of penetrating oil to make the removal of the collar nut and the sliding out of the bearing easier.

At this point you are ready to loosen the collar nut which is tightened to 210 ft.lbs. With the car lifted off the ground, the entire strut and hub assembly is hanging in the air and is only supported by the balljoints and you really don't want to attempt loosening the collar nut in this state because you may damage the balljoints. So, there's a very neat and safe way to do this:
Remove the center bmw logo cap from the rim(simply pop it out) and you will notice that the rim now has a nice hole in the center which gives you access to the collar nut. Reinstall the wheel and lower the car.

Now that the car is on its wheels, you may safely proceed to loosen the collar nut. Apply the hand brake and use a breaker bar and pipe or w/e you need to brake loose the collar nut. The collar nut is 36mm by the way, and you will need a standard(thin walled) socket. If the socket walls are too thick it won't fit. Once you break the collar nut loose, raise the car up again, remove the wheel and remove the collar nut.

At this point go ahead and remove the caliper which is held by two bolts and hang it with a wire out of the way. Next remove the disc.
Now you are ready to pull out the hub/bearing assembly.

Now, use a puller to remove the bearing/hub assembly. It should slide out very easily, I was actually able to spin the puller bolt with my hand! To be honest I was surprised at how easily the bearing came out. After reading through a few forums on this topic, it seems that others have the same experience, so don't be surprised if yours comes out very easily too… And because of this, people claim that this job can easily be done without the puller by simply attaching the rim and pulling on it. I had a puller handy, so I haven't tried, but seeing how easily the bearing slid out, it may very well be possible. (Depending on the condition of the bearing rear dust protector, you might want to replace it now)
Also, even though it is not necessary to remove the disc dust shield, this is a good chance to clean it and repaint it or replace it if necessary.

At this point go ahead and clean up the area, and proceed to install the new bearing/hub. MAKE SURE you put back the disc dust shield if you removed it BEFORE pressing in the new bearing...

Line up the new bearing so that it goes on straight, and use the 36mm socket and a mallet to gently start pressing the bearing on the axle. Once its pressed enough, use the collar nut to finish the job. (The new bearing also slides on pretty easy, so you shouldn't have problems here) MAKE SURE that when you're trying to press in the new bearing/hub assembly you apply force ONLY on the INNER RACE of the bearing!

The rest is the reverse of the install. Make sure to bend in the tab on the collar nut (use some sort of a chisel and a hammer to do this.)

Enjoy the quiet ride!