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APracing disc run-out tolerance
I've posted a few times before about a light wobble/vibration that my M3 has at about 80+mph. With any brake application at those speeds, the vibration in the steering wheel and front end is magnafied from the applied force of braking. Can't feel any feedback in the brake pedal and it's smooth at lower speeds.
I have new ARC-8 wheels, new tires, road force balanced and all checked out by my local BMW dealer for any suspension issues. Also another alignment.
I've noticed that this braking vibration has developed over the last several thousand miles, no track time ever so far.
I at this point believe it's the front disc rotors that must be causing this. The car is on jacks, I've rotated the disc by hand to see if I can feel any rubbing or grabbing of the pads. Both front disc's rotate smoothly as far as I can see. Only the left front wheel bearings seem to spin a bit tighter than the front right axis.
does anyone have any run-out tolerance data for AP? The dealership said they can measure it out and see if there is a warpage going on that can't be seen. I'd like to narrow it down to the disc's, if it is the disc's before I go buying new ones. Thanks,
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