In at least one implementation, a method of assembling gears into a housing of an automotive differential includes, selecting a thickness dimension of first and second pinion gear washers, and first and second side gear washers, locating a pair of pinion gears, a pinion shaft and a pair of side gears at least partially within an interior of the housing with the pinion gear washers between the housing and separate ones of the pinion gears, and the side gear washers between the housing and separate ones of the side gears. The thickness of the side gear washers may be a function of target side gear apex positions and relative to a pinion gear apex axis. The thickness of the pinion gear washers may be a function of target pinion gear apex positions residing along a pinion gear apex axis and relative to a side gear apex axis.