Rear axle shim source needed in Dodge Trucks Posted October 20, 2016 My Motors manual calls for .003 to .008 axle end play with equal readings at both sides to center the thrust block. There is no step by step instruction. I have both sides within specs. measured with a dial indicator now but not equal. I will probably shim tight on the side with the most end play and loose on the other thinking that there may be slight changes to the end play as the miles traveled accumulate and the new bearings seat. I don't like the imprecision of it.