Should a new wheel bearing wobble? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Before the axle is inserted and the axle nut torqued? I put in a new rear wheel bearing (using a bearing press tool) and the hub wobbles a little. Is this normal or is it a bad new bearing?

Wheel bearing has no role in controlling wobble of the hub. Check your suspension bushings.

Quotes source post: 576455

huh? perhaps bearing didn't press in straight somehow?

Quotes source post: 576455

Bad suspension bushings would cause the entire wheel carrier to move. A wobbling hub is the bearing.

^^What he said. ^^ No, the hub should not wobble after installing a new wheel bearing. Something is amiss.

My front on one side wobbled until I added the torquing force of the axle nut. Otherwise the two inner races can slightly spread and allow a slight wobble. You might be able to test it using the bearing press to clamp the inner races together and verify the wobble is gone. The 340# of torque really clamps the inner races together. Or it might be in crooked... See if you can find plates and clamp it and spin the hub and see if it resolved. I think this is why the shop manual says not to roll the car if the axle nut is not torqued down. My bearings have been doing well for the last 2 years and 30 or so track days and I was nervous about that wobble at first too.

What kind of car is it. The picture shows brake shoes. Boxster's don't have brake shoes?

Quotes source post: 576498

That's the parking brake.

There seems to be some confusion between wheel hub and wheel carrier. The carrier is part of the suspension and should have no wobble. If it does there is a problem. The wheel hub is the part that spins around and that the wheel and brake disk bolts to. If the wheel not isn't tightened the bearings that support the hub inside the carrier will not hold it firmly. In that case it will wobble and if you try to drive with it in that state it will quickly destroy the wheel bearings.

I have done 10 wheel bearing installs on different press on different cars had 2 that had slight wobble and 8 that did not. All have several thousand miles with no problem. I was worried about it at first as well.

Several mechanic folks in the local Porsche group also confirmed that the wobble can be normal. So my mind is at ease for now putting everything back together. Thanks everybody!

I have this identical problem after replacing both rear wheel bearings. Could it be a batching problem with the bearings. ? Mine are stamped FAG from Slovakia. The comments about the 2 inner races not being pressed together and being the source of wobble makes sense though. I tried pressing with the bearing puller and the wobble has gone. Hmm a bit un-nerving though. Patssle are your bearings stamped FAG brand from Slovakia. ?

[QUOTE=steved0x;576463]My front on one side wobbled until I added the torquing force of the axle nut. Otherwise the two inner races can slightly spread and allow a slight wobble. You might be able to test it using the bearing press to clamp the inner races together and verify the wobble is gone. The 340# of torque really clamps the inner races together. Or it might be in crooked... QUOTE] + 1 After you torque the wheel nut the wobble should be gone, it is important to torque the big nut 'before' you move the car

When I replaced rear wheel bearings, one of FAG bearings was not as tight press-fit as the other one. OD was a few hundreds of mm smaller, it bugged me enough to buy another and it was as tight. Also believe it or not, one of old bearings I took out of the car had one ball missing... I mean it was not there and no sign of broken pieces or otherwise... Frankly I don’t trust FAG.

Boxstard, I must say after writing my post I went down to a non Porsche standard parts supplier as they showed they had bearings in stock, amazing. The brand is a licenced Australian maker here, MKA. I bought two and installed on rears after removing the FAG ones. No more Wobble on either rear side ! That's without the axles installed and nut torqued. They WERE very wobbly before... That's amazing yours was missing a ball. ! I'm off to another branch of same store to get two more for the front. I guess I just dump the four FAG ones. The MKA's look really well machined and are fully packed with a black grease, as opposed to the meagre white grease in FAG. I think I just did an advert for MKA bearings Australia. Repco the great Australian Auto parts company that stocks them. My FAG bearings were spinning between inner sides of race and hub. The MKA's needed pulling on even after hub was in freezer. Yeah peace of mind is a lot. Well done all, especially Boxstard.! 2001 Boxster 986.