Methods for generating gear teeth of a double involute-face gear drive system, curved in their longitudinal direction in form of either shortened, normal or an extended involute curve, include methods for generating the teeth of both components. Methods for generating the teeth of a double involute pinion, shaped in form of a normal involute in their profile direction and curved in their longitudinal direction in form of an either shortened, a normal or an extended involute curve, include the use of one of the following tools (1) a face hob and (2) a conical hob. Methods for generating the teeth of a face gear curved in their longitudinal direction in form of an either shortened, a normal or an extended involute curve include the use of one of the following tools (1) a rack cutter, (2) a shaper cutter and (3) a conical hob.