Vibration under braking

[peteracs]

Hi Mark

Couple of points.

Is that with all the wheel bolts tightened up to make sure the disk is fully clamped?

Any idea on the tolerance allowed for the disk runout?

Peter

[smithymc]

Peter

You are right on it - with the bolts actually torqued to some extent, rather than just 'nipped'  which I had done with the hub spinning free, the issue pretty much goes away. Run out limit is 2 thou, 0.05mm and with a bit inevitably in the hub, I think I can get that both sides.

Mark

[smithymc]

Spoke rather too soon!

The 'good' side was pretty easy other than getting things apart as I assue this area has never been touched.

The 'bad' nearside was a pain and it seems the issue is the hub rather than the disc, as the hub face is not flat and there are some mysterous dings on the inner edge of the hub -see pics- cant imagine quite how the could have occurred, but these seem to coincide with the distortion, which is of course magnified by the time you measure at the outer edge of the disc.

As a result and to get the car back on its wheels and tested well in time for Manchester Show, I have re-fitted the old discs while I work out what to do with the hub. The result after losts of cleaning and fiddling is miles better than before but who knows for how long.

Mark

[peteracs]

Hi Mark

Maybe when a wheel bearing was replaced, but that would be unusual to have been replaced on your car wouldn't it?

Peter

[rossocorsa]

Hi Mark

Maybe when a wheel bearing was replaced, but that would be unusual to have been replaced on your car wouldn't it?

Peter

I seem to recall that on early Betas it was far from unusual for bearings to fail at 20k miles. I would suspect that there is either flange damage, a faulty bearing or the inner ring nut holding one of the bearings is loose.

[smithymc]

There is no discernible play in the bearing, although it is not as free as the opposite side.

The distortion all seems to be on the face.

Seems best to find a hub and bearing for winter shut-down.

Mark

[HFStuart]

Mark,

I might be able to help there.

I wonder if someone has tried to persuade yours off in the past with an FGH rather than a puller?

Stuart

[smithymc]

Seems feasible Stuart. Makes you wonder as it was main dealer maintained when on the road as far as I can tell, certainly in its first year with the first owner. The second who I bought it from was a master mechanic who serviced it even when it was dormant. Hate to think it was him, or indeed that he would have put up with the vibration. Then again he never went more than a few miles in it as he drove it with failing sight until he had to give up in 1982 when his sight loss became too much.

I suppose facing the hub is feasible, but I will look for another- I see Bayless have new ones at a cost.

Mark