odonnell

Tl;dr: rear wheel bearings seemed obviously failed, took it apart and nothing seems to be wrong.

When I had the rear brake rotors removed the last time I was in there, I noticed that I could grab the drive hub (with the 5 wheel studs in it) and move it up and down a few millimeters really easy, in all directions. There was also a rumbly sound from the bearing area and they didn't turn smoothly - not hard to turn, but not the feeling you would expect from greased roller bearings in good health. Same was true on both sides so I ordered everything to do the job.


Last night I stripped everything down to the trailing arms. I haven't removed the driver's side bearings yet, but on the passenger side, I couldn't find a smoking gun.

-This job was obviously done at some point...the grease was that transparent blue stuff and looked great. The seals were weathered but were still working fine.

- Nut was torqued correctly and had the cotter pin. Standing and jumping on a 2" bar did nothing to loosen it (they came off in 1 minute each thanks to a $10 VW specialty tool).

- The 3x "spacers" had no apparent damage.

- Stub axle had no meaningful wear at the areas where the bearings ride.

- Outer bearing was the correct roller bearing. No apparent damage and spun smoothly

- Inner bearing was the correct ball bearing. Again, nothing obviously wrong with it. Both bearings spun just like new. Nothing at all like the feeling I was getting with everything together.


That bothers me because I don't know what was going on. Here is something I'm wondering about... When I removed the E-brake carrier, which also contains the outer grease seal, the outer bearing basically fell out. I was able to literally just grab it out of the trailing arm. My concern is that the entire bearing was spinning with the stub axle, within the bore. Picture at the bottom shows the area where the bearing sits. It's not obviously chewed up but maybe I'm missing something. Is this something that has happened to other people?

951and944S

Did you clean the bearing really thoroughly...?

With a solvent that will get all of the grease off, then air blow dry.

It only takes a couple of pitted spots on a roller and you can't see well enough if they have grease on them.

T

ddombrowski

I had a suspected bad bearing in the front that only made noise on hard turns. We werent 100% sure it was the bearing, but for the relatively low cost of the front bearings we just decided to change them.

When we took them apart, the grease looked good, the bearings and rollers looked good, they spun exceptionally smooth. We replaced them anyway.

After replacement, the bearing noise was gone.

They can definitely be deceiving when they are in your hands vs when they are on the car.

mikehayes

I'm with these guys. You've done all the work already, replace them and then at the very least you have eliminated one possible cause for your problem. My smoking gun was that one of my axle nuts was finger tight(!). Maybe check to make sure the previous bearings were installed in their correct positions/orientations? I can't remember if it's physically possible, but maybe they got switched?

odonnell

I'll clean up the old ones and check again, either way the new ones are going in. Their orientation was correct, that was the first thing I checked. I also need to check the spacer orientation... I have them staged based on how I found them but I'll need to look up the diagram when I'm home later.


Also just bought some Loctite 39150 "bearing stick" for good measure.

Sinterpuck

I had the same exact issue with my 84 on both sides and it ended up being the other bearing that had a slight play towards the trailing arm so i used Loctite 638 to lock the bearings into place and now it is perfect.
I could also remove the bearings with my fingers with ease, i could not see anything wrong with the trailing arms and i had new bearings on both sides aswell, but yeah some Loctite 638 solved my issues.

odonnell

I re-installed the old outer bearing and sure enough, the entire assembly spun within the housing with almost no force. Took the new bearing and it was a way tighter fit, I'll have to actually press it in like I'm supposed to. Holding off until the Loctite comes in...can't hurt, since the housing is probably worn to some degree now.


This explains the noise I was getting, but not the radial play. There had to be some sort of gap between the bearing outer race and the housing for it to spin, but I couldn't get it to move appreciably within the housing despite that. Some VW forum posts indicate that some play is normal, and there is no official spec for it. So I'll just proceed and see what happens.