An electric motor assembly includes a motor shaft rotatable about a longitudinal axis, an angular position sensor rotor, and a deformable pin. The motor shaft has an axial keyway formed therein, and the axial keyway has a nominal keyway dimension. The angular position sensor rotor is coupled to the motor shaft to rotate with the motor shaft. The angular position sensor rotor has an axial key to fit within the axial keyway of the motor shaft, and the axial key has a nominal key dimension that is less than the nominal keyway dimension. The deformable pin is located in the axial keyway under compression between the axial key and the motor shaft to inhibit rotational shifting of the angular position sensor rotor relative to the motor shaft.