'Hub Run Out' what is it & how do I fix it???
Discussion
Morning guys,
getting a juddering vibration through the front wheels when I brake above 50mph. Looking at the wheels the near side front wheel has a very heavy build up of red-ish brake dust (DS25000 pads).
My pads and discs (EBD Turbo) are 5000miles new and show no sign of uneven wear. Had the calipers off and everything seems ok so I think that my hub might not be true. Have hit a few big pot holes recently.
So does my problem look like Hub Run Out? and can I fix it by getting my discs skimmed??
If I take my 350Z to my local Nissan they are going to mess about with it for 2 days and then tell me I need 4 new tyres.
cheers
Adam
getting a juddering vibration through the front wheels when I brake above 50mph. Looking at the wheels the near side front wheel has a very heavy build up of red-ish brake dust (DS25000 pads).
My pads and discs (EBD Turbo) are 5000miles new and show no sign of uneven wear. Had the calipers off and everything seems ok so I think that my hub might not be true. Have hit a few big pot holes recently.
So does my problem look like Hub Run Out? and can I fix it by getting my discs skimmed??
If I take my 350Z to my local Nissan they are going to mess about with it for 2 days and then tell me I need 4 new tyres.
cheers
Adam
You need to get yourself a DTI.
Use it with a sturdy mount to check for any variation when the axle is turned, and the DTI is placed against the hub face, then the disc face, and then the wheel rim (inside and outside)
Check for play in the wheel bearing too, and also in any of the suspension joints.
Use it with a sturdy mount to check for any variation when the axle is turned, and the DTI is placed against the hub face, then the disc face, and then the wheel rim (inside and outside)
Check for play in the wheel bearing too, and also in any of the suspension joints.
Machine Mart do some cheapie Clarke ones:
http://www.machinemart.co.uk/shop/product/details/...
It's rare to come across a buckled hub.
More likely to be warped discs, out of balance wheels or a buckled wheel.
If it was the hub, you'd be feeling it all the time, not just when you brake.
http://www.machinemart.co.uk/shop/product/details/...
It's rare to come across a buckled hub.
More likely to be warped discs, out of balance wheels or a buckled wheel.
If it was the hub, you'd be feeling it all the time, not just when you brake.
Edited by Vidal Baboon on Friday 7th May 09:58
Warped discs are a bit of a myth on road cars.
Judder is more commonly caused by Brake disc thickness variation.
As modern cars are mass produced, some run-out in the hub to which the disc is mounted is normal (it's also likely that the disc itself will have some run-out too), however; this then leads to slight run-out of the brake disc too. As a result, the brake disc then contacts the inner and/or outer pad, once per revolution, causing slight wear at these points of the disc, meaning thinner areas of disc....
This can be felt as a pulsing through the pedal as the caliper pistion moves in/out to keep the pad in contact with the disc (Judder)
If the discs are still in good health, get the discs skimmed on the car. On car skimming will do two things 1) it will give a consistent disc thickness again, and 2) it will make the disc run true, which should prevent a repeat occurance
Judder is more commonly caused by Brake disc thickness variation.
As modern cars are mass produced, some run-out in the hub to which the disc is mounted is normal (it's also likely that the disc itself will have some run-out too), however; this then leads to slight run-out of the brake disc too. As a result, the brake disc then contacts the inner and/or outer pad, once per revolution, causing slight wear at these points of the disc, meaning thinner areas of disc....
This can be felt as a pulsing through the pedal as the caliper pistion moves in/out to keep the pad in contact with the disc (Judder)
If the discs are still in good health, get the discs skimmed on the car. On car skimming will do two things 1) it will give a consistent disc thickness again, and 2) it will make the disc run true, which should prevent a repeat occurance
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