In a gear drive unit (10), in particular for adjusting moving parts in the motor vehicle, having a rotor shaft (18) supported in a housing (16) and braced axially on the housing (16) via at least one face end (50) and in which a separate toothed element (32) for transmitting torque to a gear component (38, 40) is secured to the rotor shaft (18), the toothed element (32) has an axial bearing face (48) that rests on one of the face ends (50) of the rotor shaft (18).