Brake rotor centering

[Vegas69]

Donny's numbers are correct. Those are pretty severe working angles for a performance car.

I don't agree that lowering the pinion will get you proper working angles though. From what you are saying, your driveline/pinion angle are within .5 degrees of each other on the same plane. As you lower the pinion, you will move away from parallel angles. It will decrease your working angles, but the variance in working angles from driveline to pinion will increase. Right now you have 5.5 and 6-6.5. Lowering your pinion will spread those numbers which can also cause vibrations. I'm guessing that if you drop your pinion 2 degrees to .5 up, your pinion working angle will go to 2.5 and your driveline to 5. I think your tailshaft still needs to go up to get conventional working angles.

While the angles aren't great, they are parallel and appear to be within .5-1. I think you may have something else going on since the vibration comes in at such low speed and doesn't get worse. You may have two things going on here. A driveshaft issue and then your working angles may cause you vibrations with speed. I'm no expert on this stuff, but I fought the same situation on my car. If I kept that car, I would've cut the tunnel and raised the tailshaft.