Can I install 2 different deg shims, LH and RH, to even up the caster split for alignment? root
The short answer is no. The right way to correct a side to side caster difference is to bend or twist the axle, something most front end shops quit doing in the 1960's. If the driver's side has less caster, that's a good thing. Because roads aren't as flat as a pool table, 1/2 degree less positive caster helps the vehicle "climb" the drainage crown on a road and track straight. For instance a driver's side caster of +2 1/2 degrees and a passenger side reading of +3 would be just about ideal.
Jerry
