Shim for Used 8 3/4 Gears

Is nothing engraved on the end of the pinion gear? There is a way to check it with a mic off a bar across the bearing cap as that is about as close you can get to the centerpoint. Also you can take an old pinion bearing and polish the inside so it slips on the pinion and use that as the set up bearing so you dont have to press and pull the bearing off looking for the right shim stack. My US gear took .020 shim and it was marked on the end of the pinion as well as proven with the mic across the bearing cap method.

Here is a post explaining the cap surface method: I used a square chisel as a straight edge that measured exactly 1" square. imagine that!
"..You DON'T need high tech tools to do this. Aftermarket gears have the depth measurement marked on them. This number is the measured distance from the machined surface of the pinion gear head, to the centerline of the ring gear. Common sense tells you that the ring gear centerline, is also at the parting line of the caps. So my "trick" pinion setting tool is a precision straight edge and a set of dial calipers. Lay the straight edge across the carrier, place dial caliper on top of straight edge.....roll the caliper until the "tail" contacts top of pinion gear. Read that number, subtract width of straight edge(mine is exactly 1") and there you have it. This and a set of honed bearings is ALL you need.."