You could be right on the gear mesh. The gear mesh is very tight between ring and pinion. As far as over tightening those screws. Not gonna cause it. You would have to see how TINY these screws are that hold it together. Im sure at the mere thought of over tightening them, id have a stripped diff case. The cases are VERY thin. I might buy another tomorrow, and try my luck. Expect me to be a raving lunatic if i blow another front case. I really dont even wanna bother with the truck until my aluminums come in.