whatever you do, test diff before installing into tranny. You can break it in by using a drill motor and slowly tightening diff a little bit at a time (1/8 turn) for 20 second intervals. that way, you can see if all is ok before installing. I would clean everything with motor cleaner and sand thrust washers and diff rings with 500 grit. if you have only used one side, flip and sand the side that has not been used. use plenty of correct grease on the rings and balls (on top of balls make sure you have a nice amount of grease all the way around). if during break in it becomes gritty, replace both diff balls and thrust balls. I use stock ae stuff and change out when necessary since I run stock and not too much stress on the diff to warrant carbide. once you have completed breaking it in, secure diff outdrives with a couple of hex wrenches and try to turn the actual gear. if it moves, tighten it. back off slipper all the way then install and adjust slipper. if you are running stock, and you have tightened the diff sufficiently, the diff should not bark. the whole concept is to tighten the diff enough that the slipper gives before your diff barks. run slowly on track for a couple of minutes and recheck tightness and adjust if necessary. I run a slipper eliminator and have my diff tight enough that a stock motor can not cause the diff to slip and damage balls or rings. good luck