[olddog]

Be aware that some gear ratios are timed. The number of pinion teeth verses the ring gear teeth are such that the same teeth always contact each other in a repeating pattern. Do not pull the pinion without first knowing how (if needed) to time the gears.

Second thing. The pinion flange has shims, not gaskets. This is what sets how the teeth contact each other. Do not change the shims or put sealer on the shims. It seals with an "O" ring internally.