An improved gas spring has a drive motor for driving a piston. A piston head has a thread at an outer periphery that is guided along a mating thread in an inner periphery of a cylinder. The piston is caused to rotate relative to the cylinder, and is guided for reciprocating movement. In this manner, a drive motor is incorporated into the gas spring such that the gas spring has both a driven and a manual mode. The inventive gas spring has particular application in attaching a vehicle closure to a vehicle frame.