Front hub run out out of spec.

[gfiandy]

Hi I recently fitted a new set of EBC discs to the front of my spit. However one of them was causing a lot of pad noise.

It works ok and recently passed its MOT but I could see it wasn't running true against the calliper. Initially I though I must have got a bad disc but EBC tell me they measure them all befor shipment so this was very unlikely.

So I checked the run out on the disc and the hub the disk show 0.3mm spec is 0.05mm and the hub about the same it's a bit harder to tell as the hub surface has some corrosion even after cleaning but it definitely shows the same displacement as the disc. The disk mating surface is not corroded and after cleaning the original turning marks are clearly visible. I ran a flat file over it to pick up any high spots but could not find any.

So what do I do the hub is a massive casting I can't see how it could be bent as it shows no signs of damage.

Does this mean the bearing seats are wrong. I think the bearings were replaced by the PO. I can't see any obvious problems with them but I can't think of any other cause.

Any ideas?

Regards,
Andrew

[Dannyb]

swap the discs over that will tell you if the hub is the problem. The hubs do wear inside where the bearing sit.

[Velocita Rosso]

1684 wrote:

swap the discs over that will tell you if the hub is the problem. The hubs do wear inside where the bearing sit.

They can` t as the bearing runs on a separate race
The stub axle can wear where the inner and outer bearings run

[Dannyb]

michael_charlton wrote:

They can` t as the bearing runs on a separate race
The stub axle can wear where the inner and outer bearings run

Then tell me how one of my front hubs would not hold the bearing race. It would just fall out, and I could not get the bearing adjusted right because the whole thing just revolved including the race. Possibly caused by over tightening of the bearings throughout  it's life.
New hub fixed the problem.

[Velocita Rosso]

1684 wrote:

Then tell me how one of my front hubs would not hold the bearing race. It would just fall out, and I could not get the bearing adjusted right because the whole thing just revolved including the race. Possibly caused by over tightening of the bearings throughout  it's life.
New hub fixed the problem.

Not quite what you said..."where the bearing sits"
What you mean is where the race is located.
As the race is a tolerance fit there must have been something wrong with the hub in the first place
The race has to be pressed/ hammered into place so it is quite a tight fit
Sounds like a previous owner misdemeanour

[gfiandy]

So should I replace the bearings or the stub axel?

The bearing shells are not loose and there is no play in the bearing on the stub axel.

It is definitely the hum that is out of line as I measured it with the dial gauge.

Regards,
Andrew

[Velocita Rosso]

2674 wrote:

So should I replace the bearings or the stub axel?

The bearing shells are not loose and there is no play in the bearing on the stub axel.

It is definitely the hum that is out of line as I measured it with the dial gauge.

Regards,
Andrew

It could have been faulty right from original assembly
The hub could have been machined off centre,which is easy done
If there is no stepped recess on the axle and is perfectly symetrical then it may mean a new hub
If you have a spare or able to change opposite side then that would be the only check..........apart from buying new

[gfiandy]

Thanks, I will try swapping them from one side to the other.

Andrew