Jump to content
The mkiv Supra Owners Club

Brake disc and hub run-out


richardharmon

Recommended Posts

I have been experiencing mild brake pedal vibration under heavy braking so I measured the brake disc run-out. The drivers side seems way off the scale at about 0.20mm (instead of the 0.05mm spec). This would explain the vibration. I couldn’t reduce the run-out by moving the disc round in each of its 5 positions so I measured the hub run-out and that’s right on the limit (0.05mm). I suspect that if the discs are true then the run-out at 10 mm from the outer edge of the disc is always going to be more than at the hub (seems to make sense to me anyway)? The vibration does get worse when the brakes are hot but that would point to the discs, not the hub, wouldn't it?

 

Could a dodgy bearing cause the run-out at the hub or is it more likely that the hub is buckled? How easy is it to change the front wheel bearing, anyone done it themselves or do you need some sort of press to seat the bearings?

 

Any suggestions or experiences in this matter would be appreciated.

Link to comment
Share on other sites

It won't be the bearing, it will be the hud wheel flange itself. If you remove the hub, press out the studs and get a good machinist to true the wheel flange up in a lathe it should be re useable, but to be honest, given the hassle factor, it may be better to just buy a new hub. None stock wheels and overtightened hub nuts are common causes of warped flanges. You are right, run out and Y mm from the hub centreline will be a lot greater at 3x Y mm from the flange centreline.

Link to comment
Share on other sites

Measured on a 110mm dia. (IIRC) the hub runout should be no greater than 0.04mm. I found both mine to be within this after a little attention with some emery to remove rust high spots and the like.

For what it's worth at about 350mm dia. I got a hub runout of 0.03mm. The specified max from AP is 0.07mm.

They recommend indexing the disc on the hub if you're getting v.close but not quite.

 

Regards,

 

Tony License

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.