Alright so, I built up my HF SS, but I'm just confused about the diff crown gear meshing with the pinion.. I shimmed it as per manual (shim on the side of the crown), but when I rotate the pinion, it grinds. I moved the shim to the other side so it can mesh away from the pinion some. It helped, but it still somewhat grinds. Should I worry about it? How can I fix this?

Oh, and in-case anyone wants to see, here's the finished product (less engine, and servos).