Patent ID: 7155824

Claim:
A method for fabricating an automotive differential having an input pinion, the method comprising: providing a tubular shaft; roll forming the tubular shaft to define a plurality of spline teeth; machining a pair of axially spaced apart bearing surfaces onto the tubular shaft, each bearing surfaces being configured to engage an inner race of a bearing, the bearing surfaces being located between the spline teeth and an end of the tubular shaft opposite the spline teeth; forging a pinion, the pinion including a plurality of teeth, each tooth being formed in the forging step to a size that is larger than a desired tooth size by an amount that is less than or equal to about 0.04 inch; performing at least one of a machining operation, grinding operation and a honing operation to machine the teeth of the pinion to the desired tooth size; forming a round hole in the pinion; pressing a cylindrical end of the tubular shaft into the hole in the pinion to fixedly couple the pinion and the tubular shaft to one another; induction heating the pinion and the tubular shaft to heat-treat both a plurality of teeth that are formed on the pinion and at least one portion of the tubular shaft; laser welding the tubular shaft to the pinion; and meshing the pinion with a ring gear.