Mitch Johnson

I "adjusted" the front bearings today, had a lot of play enough that an alignment wouldn't happen. The biggest challenge to that is getting the godforsaken dust cap off. Turns out a 1 7/8" muffler clamp and large pry bar did the trick, got it started on one side and the damn thing nearly fell right out.

jpitman2

Replacing bearings shouldnt need an alignment, unless one was done with the bearings badly worn/out of adjustment. I have seen other makes recommend .003" end float in a hub when cold, iron hub, not alloy as in 928s. If there is race wear on the spindle such that the inner race can turn , try putting a few dimples in the area with a centre punch, so that you need to tap the inner race into place, may save the spindle. Also Loctite do bearing holding/fixing stuff.
jp 83 Euro S AT 50k

auzivision

I replaced my wheel bearings today, but is was on my daily driver (2000 Mercedes E430). Never done this kind of work, so it was a big time learning expereience. Hopefully, now I can get to work on the fun car.

Niels Jørgensen

I'm in the middle of replacing the front bearings ... again ... Figured I might as well append my questions to this thread, in case someone else can use the answers.

1) Both front bearings were changed only 2 years ago, by a reputable shop that I've used since I got the car. Is this normal? Could there be something else wrong that might wear the bearings down prematurely?

2) Is it a good idea to remove all the old grease? (It's mostly brown and looks to be "contaminated" with, probably, rust (suggesting water in the hub? Bad seal? Is the hub shot?)

3) Should the hub be completely filled with grease when re-assembled?

JHowell37

1. Sometimes you do get bad bearings. Making bearings isn't easy and the slightest defects can cause early failure.

2. It's a good idea to try to remove as much old grease as possible to get rid of contaminates that got by the old seals.

3. NO. When it comes to grease the most important thing is to make sure the new bearing is properly packed. The best way to do that IMO is to use a bearing packer. If you pack the hub full of grease, your only accomplishment will be making a mess.

jpitman2

Most tapered roller bearings fail from being TOO tight, or water & dirt contamination. Dont know about alloy hubs, but with cast iron hubs, I have seen optimum set up listed as .003" end float cold. The cold float is derived from the required float when up to hot working conditions under load.
jp 83 Euro S AT 50k

StratfordShark

Since doing this the improvised way I've bought a tool for removing the dust cap (looks like giant pair of pincers which work beautifully).

I only bought it because I'm a sucker for tools! Before I bought it I followed the advice to remove the dust cap by using a short extension from a 3/8inch socket drive kit (fits well in the 'well' of the dust cap). I marked 3 points 120 degrees apart roughly on the cap. You place the extension at one of these points, tap a couple of times with hammer, then move round to next point. After a couple of goes at each point the cap just pops out.

StratfordShark

The bearings shouldn't wear that quickly. I understand that properly lubricated bearings should last practically forever! I changed mine recently as a WYAIT when I fitted new rotors and dustshields but the original 20 year old ones still looked perfect under magnifying glass.

Very good idea to remove all the old grease - use a proper degreaser to clean the bearings and wipe out the hub. It could be the seal is bad but you have to replace the seal anyway when it's removed (I had to get a shop to pull mine it was in so tight).

The hub shouldn't be packed too tight. I think you're meant to fill about half of the space between inner and outer bearings with grease.

Niels Jørgensen

Got the new bearings today, but I messed up and only ordered for one side so I'm waiting again

I also realised that I had not taken out any of the bearing races - Dirty as it was, I never realised it was a separate part, I thought it was part of the hub (goes to show what I know about bearings), so now I got more questions:

1. The old bearing look fairly fresh (save the rust-colored grease), but the race does have a lot of discoloration - same on the spindle. Am I in deeper trouble than just a wheel bearing here?

2. Cannot for the life of me find someone who sells bearing packers - What's the alternative?

3. I put the new races and seal in the freezer, and intend to use a heat gun to warm up the hub - is that going to work?

Niels Jørgensen

Lol, after all the trouble I had getting first a second set of bearings, then the correct one in place of the first set I got, it turns out the right side bearing is ok, but loose.

I tightened it 3/4 of a turn with my fingers then tightened the allen bolt to spec.

This also cleared up the mystery of the 2-year lifespan. Now that I think about it, it's clear to me that what was changed 2 years ago was the right side only.

And best of all, the vibration is gone