Quote:
Originally Posted by fortythirtyfive
Took the wheel off tonight so I could sand the surfaces down on the outer brake hub, then place the second friction plate between the brake disc and 10mm spacer.
When I went to break the tension on the wheel nuts it clicked! So now I'm wondering if it is related to the wheel nuts, they're definitely not too long but I suppose it could also be me creating this so called "microscopic disc movement" when putting pressure on the bolts.
The noise has once again gone now since reinstalling the wheel, but I can only imagine it will be back soon  |
I see from your signature that you have spacers on the wheels, there is quite a dangerous condition that could be causing the noise. It is dangerous enough that I saw an M2 lose a wheel at 140km/h on the track in July due to this problem, causing thousands of $ in damage to the bumper, suspension, wheel and brake, but luckily the car was brought to a stop without a crash.
The hubcentric flange on some wheel spacers has a chamfer that is larger than the chamfer on the wheel, this causes the wheel to not sit flat on the spacer, putting excess force on the wheel bolts (or in the case of the M2, the stud conversion kit). Eventually the bolts or studs will fail from cyclic fatigue loading as the wheel moves about a very small amount on each rotation.
Here is a method from Bimmerworld to check if you have a problem, besides looking at both the hub chamfer and spacer chamfer for signs of fretting (small movements that will produce abrasion marks):
If this is the problem, the spacers should be replaced with ones that don't have the problematic chamfer and all wheel bolts that have been used with the spacer should be replaced too, due to unknown loading conditions that may have weakened them.