Originally Posted by 2-Bad

The kit diff shims external diameter are too narrow and in my experience eventually cone in towards the cavity of the o-ring in the diff housing. This causes the diff to become notchy and tight.
You need to find shims with the same internal diameter, but a larger external diameter, as this will allow the shim to be more supported against the housing and not cone into the o-ring space.
Then it's just a matter is sanding the gears and/or shiming to get the smoothest feeling diff. Too tight or loose its notchy...

Hope this helps...