Moving Break Discs

[dark andrew]

I've just changed my wheels and noticed that the discs on the rear wheels have about 4-5mm rotational play in them, this appears to be caused by having a 2mm (or there abouts) clearance around the wheel studs where the disc assembly fits over them. I thought maybe the wheel nuts would extend through the wheel and into this gap around the studs, and so lock the disc in place, but they aren't long enough. Is this normal or should the disc be locked onto the hub somehow?

[GIDDLEPIN]

Nope, they are all the same, the main point of fitting is the centre spiggot, if this had the same clearance you would have a bucking bronco when you were driving.

You can just see the same stud clearance on my new rear discs CLICKY

Les

[Chris81]

Hey, just came across this thread whilst searching for help with the same thing on my Yaris. Its the front disc on mine, I was surprised to see the bolts move around in the disc hub. Checked all 4 wheels and only 1 displayed these characteristics (the other 3 sets of studs felt tight in place) which made me think there was a problem. So is it totally normal for the studs to move around in the hub? And why are the holes in the disc hub wider than the studs???

My post below:

http://toyotaownersclub.com/forums/index.php?showtopic=69761

[Parts-King]

I think you are confusing two matters. The disc will move on the hub so you will be able to rock it back and forth, the studs in the hub, SHOULD NOT move, as they are a tight fit into the hub and have to be knocked out (an interference type fit) I think that is what you are trying to say, or is it me confusing two issues??? Kingo

[cfc1]

Here is a typical car hub...

.. you can clearly see the studs attached through the hub.. these pressed in and locate on a spline and shouldn't move separately from that part of the hub. The brake disc then fits over the top of this hub, the studs go through the corresponding holes in the disc, (these holes are a little wider than the studs) to hold the disc in place there is sometimes a small grub screw, but not always. The brake calipers then get mounted on and sit astride the disc holding it loosely in place.. it is only when the wheel nuts are in place and fully tightened that there is no play.

If you have play on any single one of the studs.. then it needs to be knocked out and a new one pulled in... if there is play on the full hub assembly (as in the picture.. not the disc) then check the wheel bearings etc, if it is only the disc thats moving it is fine.. other than the possibility that a grub screw hasn't been replaced.