In reply to adam525i (Forum Supporter) :
I want to reply (again) to Adam. I misunderstood what shims you were talking about and, to be frank, I had never considered them. The shims you're talking about are the shims between the side covers and the case. Ed Higginbotham and I got deep into this issue and I contacted RacingDiffs to get some clarification. They sent me this video link (below) that explains it pretty well. It starts about 37 minutes into the video, which is really about changing ratios, but at this point he goes into the purpose of those shims and how they are used to adjust preload on the pinion. I must have gotten extremely lucky because both times I have done the 6-disc upgrade I didn't have to change the shims.
