Shimming the coil spring will have no effect on the pinion angle. As Eddy said, you have to either shorten the trailing arm to raise or lengthen to the trailing arm to lower the pinion angle. It's not that difficult to do the ovalling that he's talking about. I've got to do it on mine because of a vibe @ 65mph. I've got new joints, but they do it too. Not as severe as before, but it's only a matter of time before they get worse... Just gotta find the time <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

Fasteddy's advice is occasionally sound...