When ever the ring and pinion gears or the pinion or differential case bearings are replaced, pinion gear depth, pinion
bearing preload, and the ring and pinion gear tooth patterns and backlash must be checked and adjusted.
this holds true for all types of differentials except most FWD differentials that use helical-cut gears, and taking
tooth patterns is not necessary. Nearly all other final drive units use hypoid gears that must be properly adjusted to
ensure a quiet operation.