Wheel bearing rebuild

[phil-m]

Considering the price of new wheel bearings I decided to see if refurbishing one was a viable job. Having got the bearing out of the hub it becomes apparent just how over engineered it is for the job! There is no obvious method or signs of how to disassemble it but it looked like the easiest way in was to remove the shields. These are thin rings 'sprung' into place and with a rounded spatula/pick I managed to pry it out without damage, the next thing to remove is the seal, this appeared to be a rigid plastic disc sat between the external shield and an inner shield. This disc acts a seal and the 2 metal discs act as supports. Once the seal is out the inner shield can be popped out. With these out you are into the bearing proper. First remove the inner races followed by the beautifully made brass bearing cage and the balls themselves. Once it was all cleaned up it became clear there was little if any wear or brinelling to the raceways. The biggest issue  was how to replace the seal? I thought about machining a disc out of engineering plastics but once I stripped down the other hub it seems the seal is rubber and in the first bearing I looked at it had hardened and broken up. I made news from aerospace grade Viton in the correct thickness. Reassembly was quite straightforward other than refitting the outer shields which is a bit of a 2 man job to feed it/tap it/spring it back into place. Definitely worth the time compared to new bearings.

[simonandjuliet]

Sounds interesting, I know they are substantial bearings  - any pictures ?

[lancialulu]

I rebuilt some on the rear of my HF as the MOT man said they were noisy and a fail. Rebuilt them and they were still noisy! AFAICS there was little or no wear apparent. Replaced with a new set and got the pass. They maybe over engineered but still suffer same wear issues esp for a car that has stood for a length of time.

[chugga boom]

my dad has a fairly simple solution for re greasing the bearings which is a vets hyperdermic needle ( big bore) on a grease gun which can be pushed either through or around the seal, if you leave the bearing soak in degreaser 1st and put them through the parts washer most of the dried up rubbish will come out, complete strip is always better but the needle idea certainly works well

[ben]

You dont say why you were trying to refurbish the bearings in the first place.
If they were noisy  there would almost certainly be damage to the balls or the raceways which you would not necessarily see without some degree of magnification and an experienced eye.
If your overhaul is just because they have been unused for a longish time cleaning and re-greasing may be all that is required.

[phil-m]

It was just an overhaul from them being stood, I did have the races checked dimensionally along with hardness checks. As you say though if the bearing is noisy then other than replace the balls there is little you can do

[phil-m]

Here are some images of the rebuild;

[simonandjuliet]

The ball-cages are beautiful. If they are still noisy after you refit them, you could make your wife a lovely pair of earrings instead ....

[ben]

Generally when re-greasing rolling contact bearings it is important not to fill them right up with grease.From memory only about half the total  volume available should be filled otherwise the bearing will overheat and try to pump out the surplus through the seals.

[phil-m]

Very true, I weighed the bearings before strip to get an idea of how much grease to use.