A method of assembling gears into a housing of an automotive differential , comprising: providing a first pinion gear washer and a second pinion gear washer ; providing a first side gear washer and a second side gear washer ; locating a pair of pinion gears and the first and second pinion gear washers on a pinion shaft at least partially within an interior of the housing , and locating a pair of side gears at least partially within said interior and meshed with the pinion gears ; situating said first pinion gear washer between said housing and one of said pinion gears , and situating said second pinion gear washer between said housing and the other of said pinion gears ; situating said first side gear washer between said housing and one of said side gears , and situating said second side gear washer between said housing and the other of said side gears ; characterized in doing at least one of: determining an actual side gear apex position and comparing the actual side gear apex position to a target side gear apex position, and if the actual position and target position differ by more than a first threshold, selecting a thickness of one or both of the first side gear washer and the second side gear washer to move the actual side gear apex position to a position within the threshold from the target position; and determining an actual pinion gear apex position and comparing the actual pinion gear apex position to a target pinion gear apex position, and if the actual position and target position differ by more than a second threshold, selecting a thickness of one or both of the first pinion gear washer and the second pinion gear washer to move the actual pinion gear apex position to a position within a threshold from the target position. providing a first pinion gear washer and a second pinion gear washer ; providing a first side gear washer and a second side gear washer ; locating a pair of pinion gears and the first and second pinion gear washers on a pinion shaft at least partially within an interior of the housing , and locating a pair of side gears at least partially within said interior and meshed with the pinion gears ; situating said first pinion gear washer between said housing and one of said pinion gears , and situating said second pinion gear washer between said housing and the other of said pinion gears ; situating said first side gear washer between said housing and one of said side gears , and situating said second side gear washer between said housing and the other of said side gears ; determining an actual side gear apex position and comparing the actual side gear apex position to a target side gear apex position, and if the actual position and target position differ by more than a first threshold, selecting a thickness of one or both of the first side gear washer and the second side gear washer to move the actual side gear apex position to a position within the threshold from the target position; and determining an actual pinion gear apex position and comparing the actual pinion gear apex position to a target pinion gear apex position, and if the actual position and target position differ by more than a second threshold, selecting a thickness of one or both of the first pinion gear washer and the second pinion gear washer to move the actual pinion gear apex position to a position within a threshold from the target position. <EOS>