At the end of my last track day I developed a bit of a vibration that got worse towards the end. On inspection the rear right disc and bearing carrier were much hotter than the other side, so I did a bit of digging when I got home. The rear hub was stiff and wouldn't spin freely even with the driveshaft and calliper removed so I ordered a bearing from Burton power and replaced it. I also cleaned up all the pad carrier and slide pins on the calliper incase the calliper had been sticking a bit.

After about a hundred miles on the road there still feels like some vibration is there. The disc was still slightly warm as well. Stripping that side down again, the new bearing still feels quite stiff and graunchy. What's the most likely cause of this? A few things I thought of were;

a) over torqued it, causing it to bind slightly
b) it needs to do a few more miles to loosen up a bit
c) knackered the new bearing with the sticky calliper heating it up
d) something else...

It's a High torque on Sierra rear wheel bearings as the races are a machined fit, when new they are indeed stiff for the first few hundred miles.

Graunchy does not sound good knock off the halfshaft to make sure it's not something further back in the drive line.

I've taken the drive shaft and calliper off. It's definitely the bearing that is stiff.

Go with b)

It will sort itself out, my new bearings were very stiff when replaced.

If the car has a viscous LSD you need to have both wheels off the deck and out of gear before you check for free rotation,

It sounds more like the original problem was brake related.

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Originally posted by britishtrident
If the car has a viscous LSD you need to have both wheels off the deck and out of gear before you check for free rotation,

It sounds more like the original problem was brake related.

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Give it a few more trips out and see if the bearing frees off

Had another look at it this afternoon and it felt very 'notchy' when rotated, almost as if I could feel the individual rollers moving.

So I've stripped it out and will hopefully have a new one to put in tomorrow. The grease smelt pretty horrible, so wonder if the brake has still been dragging a bit and heated the hub up enough to knacker the bearing.

How did you press the new bearing in? If you pressed on the inner race there is a chance you damaged one of the races, bearings should be pressed in by pressing on the outer race

I used the old race as a drift, so perhaps not ideal. Might be worth trying to get this one pressed in?

It didn't feel bad initially, just a bit stiff, hence my thoughts that it might have been heat causing the issue.

may be worth checking the seat the bearing is pressed into making sure it is clean. The preload is set buy these clearances a bit of crap/rust might be enough to set to high a preload knackering the bearing.

Dan

Right, so I've got he he new bearing in and it feels much better. I think I probably put a bit too much grease in the last one (compared to the supplied packet of grease I used today) which may not have helped matters. Also cleaned up all the calliper slider pins and the channels the pads sit in to rectify any brake drag. I'll see what happens tomorrow if it's dry...

After a mile, I had a quick check that everything looked fine and found the rear disc was still excessively hot. So that'll be what knackered the bearing then. Time to rebuild the calliper tomorrow and see how that goes.