MacWorld

Since I replaced all 4 wheel bearing of my UrS this weekend I can give advices to those that are thinking of doing it. May be this had been all said.

- All 4 bearings are the same. 82mm outer diameter and 43mm/45mm inner diameter.
- Remove rust on the side where the bearing will be exiting before pressing
- You will need at least a 20Tons press. Since my 20tons press was not enough, I heated the knuckle around the bearing until it started to move.
- I recommend wearing eye and ear protection with the press, the noise generated when the bearing starts moving is really loud (since it's amplified by the press's structure)
- You don't need to remove the ABS Sensors from the knuckles
- Press off the hub first (push it with a big round metal part like a 30mm box) then press off the bearing pushing on the inner race the same side you pushed to remove the hub. The inner race and it's ***** will be strong enough to hold the pressure.
- Before installing the new bearing make sure to remove all rust on the side which the bearing will be entering the knuckle. I use 36 grid sandpaper to remove it by hand. Do not sand the part where the bearing will sit, only the section that the bearing has to go through in order to get to it's place.

Front:
- Held in place only by friction. No bolts, no snap rings.
- DO NOT LUBRICATE THE OUTSIDE OF THE NEW BEARING. You can guess that you must not lubricate the inner part of the knuckle!
- Bearing will exit the knuckle only by the wheel side.

Rear:
- Held in place by snap rings and friction. My car had 280 000km and the snap rings were rust welded in place. I was not able to remove them with small torches nor zip-gun (I use this technique on A2 VW's and it works all the time). I had to get them removed by a friend working at a dealer by heating the parts to the point where the rust breaks itself apart.
- I highly recommend replacing at least the outer snap rings as you will probably destroy them if they have never been replaced.

Trick:
If the wheel side inner race of the bearing stays on the wheel hub (will do 95% of the time) you can remove it from there with a zip gun. Place the hub in a vise and use a flat bit on the zip gun to drive the bearing race off the hub. You simply need to hammer on the largest part of the race. If you are careful you will not damage the hub and if you damage it a bit, simply file off the bumps. The race doesn't move on the hub so as long as it is in the same position on the hub it will be fine.

Sorry if my sentences are weird, I am used to speak French.

racerock

Your English is better than my French.

Thanks for the hints. Doing mine now.

racerock

Meant to add that my 2000 A4 Quattro does not have snap rings. Trying to confirm which side it is pushed from. The hub pushed out (obviously...), and believe the bearing is pushed out as well.

Yep, my 1 race stayed on the hub

mchaloux

Good work, thanks for taking the time to put this together. You should see what some of the anglais write, (you did pretty good.) :>