Methods of manufacturing hypoid gears

A method of manufacturing a hard finished hypoid gear comprising:

• face hobbing a gear blank and forming a green hypoid gear with green gear teeth;
• heat treating the green hypoid gear to form a black hypoid gear with black gear teeth;
• hard finishing non-tooth features on the black hypoid gear;
• shot peening the black hypoid gear;
• and
• hard hobbing the black gear teeth to form the hard finished hypoid gear,
• wherein heat treating a root region of the green hypoid gear forms a root region of the black hypoid gear,
• wherein face hobbing the green hypoid gear removes material from the root region of the green hypoid gear and hard hobbing the black hypoid gear does not remove material from the root region of the black hypoid gear.

A method of manufacturing a hypoid gear comprising:

• face hobbing a gear blank and forming a green hypoid gear with green gear teeth;
• heat treating the green hypoid gear to form a black hypoid gear with black gear teeth;
• hard finishing non-tooth features on the black hypoid gear;
• shot peening the black hypoid gear;
• and
• hard hobbing the black gear teeth to form the hypoid gear,
• wherein heat treating a root region of the green hypoid gear forms a root region of the black hypoid gear,
• wherein hard hobbing the black gear teeth comprises rotation of a cutting tool with a plurality of outside cutting blades such that an inside cutting blade completes a cut of a convex side of a black gear tooth before an outside side cutting blade begins a cut of a concave side of the black gear tooth,
• wherein face hobbing the green hypoid gear removes material from the root region of the green hypoid gear and hard hobbing the black hypoid gear does not remove material from the root region of the black hypoid gear.