Do you have the silver or the black PL600? On the black one, there is really no way to adjust the azimuth except to make micro adjustments by loosing that little screw at the top of the head shell adjusting the headshell one way or the other, and then tighten the screw again.
However, you mentioned shims in your OP, which really don't have anything to do with azimuth, but more with VTA. Also, have you tried the pioneer experts forum?
However, you mentioned shims in your OP, which really don't have anything to do with azimuth, but more with VTA. Also, have you tried the pioneer experts forum?