[kwmech]

All the shims go between the bearing and the case on the nut side of the shaft. So you have to put the gear in with the shims stuck somewhat to the bearing with a touch of grease to hold them in place the shove the shaft in from the bottom all the way through without damaging the shim, then tighten the nut to about 100 lbs torque. Check endplay, you don't want or need preload on the bearings and you don't want it excessively loose to where the gear goes back and forth in the case.