bump

 

I have the same vibration at 60-65 mph with a 2" shackle. I recently rotated the tires front to back and it became worse even though my fronts where new and balanced this spring. When my tuner saw the vibration on the dyno, he suggested a bent axle, as it seemed to come from only the right rear wheel.

 

I had a vibration at 65, but that went away when I got my tires rotated and balanced. Now it is at 30, so I think it is a pinion angle problem. My angle is 5.7 degrees, is that right?