Rear hub bearing

[jonno]

Hadn't been able to get 4th gear last weekend at Santa Pod.So when I stripped the bottom end down I was expecting sliding dog problems.What I wasn't expecting was the rear hub race all fouled up,and about a third of the ball bearings missing.I hope they're in the drained out oil Lucky they didn't jam up the gears causing damage .Anyone had this problem,or ant suggestions on what caused it?

[Scooter Paul]

Was it a complete failure of the bearing race? I've never seen this.

Paul

[jonno]

Everything seemed fine 1st 2nd 3rd all ok just couldn't get 4th.No noise,rear wheel felt tight now and then but that was rear brake I think.

[Scooter Paul]

It's hard to tell from the upper pic but is that a chunk missing from the inner race? If so Im pretty stunned this could have happened. If not how did the balls escape from between the two races?

[berniek]

I have never seen a failure of this nature. Do you know the origin of the bearing?

[jonno]

The gap is where the balls were.They must have been ground up as r=there was a fair bit of metal dust in the oil..Yes how did the balls get out of the races?

[Ken Tucky]

A new one for me too John ....................and as you know I've almost broken everything in there over the years.
No wonder you were struggling, it wasn't just the wind eh.............
Gotta wonder where the bearing 'really came from' ?...............
Richard

[sunrisemac]

have a look at a good bearing, the link below shows one, and I think you'll see that the cage (the bits of steel strip you have pulled out) holds the balls apart so I don't think any balls are missing they are just all bunched up

http://simplybearings.co.uk/shop/produc ... wwodIm4AHg

[jonno]

Could the bearing failure cause any damage ie bend the lay shaft? Ive replaced the bearing and put the lay shaft in and it seems ok.

[Scooter Paul]

I'd button everything up and check for a true run out on the rear hub i.e. spins true and without play. As a precaution I'd also change the end plate bearing and check that the end plate studs haven't ovalised the holes or worse broken the casting. I think it would take something to bend the shaft. Maybe someone else has experienced a bent shaft?

[Dazts1]

I had exactly the same failure back in 2000 at the IOW. The reason I went into the motor was clutch slip. Upon taking the side case off I found lumps of metal. This resulted in a gearbox strip to find exactly what u have going on. At 1st I presumed some balls had come out. On counting up the balls against the new bearing they were the same , it was just the cage that had failed. I never got to the bottom of why it happened , I just put it down to been an Indian bearing . Which at the time was all that was available new. Or a good secondhand Italian

[Dazts1]

I rebuilt on the IOW site with all the same parts ,I had no choice as 330 mile home. I had no real way of checking the layshaft on a campsite for true. It never failed me again. But as soon as good bearings become available it was a must have for me having had this happen. Gearbox could have jammed with bits of bearing floating about. Not good !

[jonno]

Have put it all together and there are no tight spots .I suppose any movement would have been taken up in the tolerances of the gearbox,selector and end plate.There doesn't seem to be any damage on these parts,so should be good.