A mechanical actuator for translating rotational motion to linear motion. The actuator includes a motor, a screw assembly, a bearing assembly, and first and second lubrication systems. The screw assembly includes a housing, a threaded screw shaft disposed within the housing, a nut assembly, and an extension tube. The threaded screw shaft is rotatable by the motor. The nut assembly is arranged to move in either direction along a longitudinal axis of the threaded screw shaft when the threaded screw shaft is in rotational motion, thereby moving the extension tube between an extended position and a retracted position. The bearing assembly is arranged to provide support to at least a portion of a length of the threaded screw shaft. A pathway of the first lubrication system is remote and isolated from a pathway of the second lubrication system.