Abstract: A steel torsional element includes a first or shaft portion for transmitting torque and a second portion, such as a gear, for transferring torque to another machine element. The entire torsional element is carburized and quenched to a first depth to provide wear-resistance and resistance to surface compressive fatigue in the second portion for the transferring of torque to another machine element. The quenching operation also provides a strong but ductile core for both portions of the steel torsional element. The shaft portion is then induction hardened to a second and greater depth to increase the torsional strength thereof.

Abstract: A planetary outer end of the type commonly utilized on heavy duty drive axles has a plurality of members that include a planet carrier assembly having a planet carrier housing and an abutting carrier plate rigidly attached thereto wherein the improvement takes the form of hardened high strength hollow dowel pins that are press-fitted relative to both the carrier housing and the carrier plate for locating and securing the carrier housing and carrier plate against angular movement relative to one another with a plurality of cap screws extending axially freely through the hollow dowel pins for axially fastening together the carrier housing and carrier plate, whereby the dowel pins are subject only to torsional shear loading while the cap screws are subject only to axial tensile loading thereby producing a structure that approximates the strength of a unitary planet carrier.