OT: How to adjust 901 shims, on the intermediate plate? Options

[olav]

Was wondering how the factory figured out how many shims to put in the case side intermediate plate in the first place?

And what are they shiming anyway? Does it make that much of a difference?

Just curious?

[Cap'n Krusty]

They use a fixture that goes in in place of the diff and holds a dial indicator set with yet another fixture. The pinion depth is measured, and compared to the depth determined during manufacture to be the quietest running, longest wearing, and most appropriate. It's marked on the pinion and/or the ring gear. The pinion head shims do most of the adjustment, and the paper shims fine tune it. Once it's properly set, the ring gear preload and backlash are set. Carefully and accurately measuring the old paper shims should get you into safe territory. The Cap'n