Just push the pinion gear then push the rear drive shaft set the grub screw. When you start shimming place three shims on left one on the right or until there's no movement from side to side it should be a tad hard when you place the diff in the case. start from left to right (looking at the ass) take from the left add to the right until you feel the high spots or when its notchy. Use mobile synthetic grease place cover make sure you don't over tighten bottom and top screws. When you spin the rear you should feel a light notch it will wear. I followed this simple method change the rear setup every year just to change everything was still good. Also use the alu rear diff inserts for me helped my diff never clicked