741 - crush sleeve and shims?

when you set the pinion bearing preload on a rebuilt differential with new bearings ( 20-25 in /lbs ) it will feel tight --- you have to do a proper break in of the differential as new bearings build a lot of heat initially and you can ruin your new bearings and gear in minutes .

before you send the differential out check the preload and if it is in range leave it alone . it will ease up as the miles go by and eventually go to zero.

your "diff guy" should have put a in/lb torque wrench on it and checked it that way while you were there and gave you the actual info not "on the high side "--- going by feel is not the way to do things unless you are stuck in the bush / outback and you have to get home.

if you are going to have a differential rebuilt ,,,the one question you should always ask a "diff guy" is what do you set the pinion bearing preload at -- if he says tight or can't give you an actual number --- find someone else who understand the importance of this procedure.