Anti-backlash actuators reduce vertical backlash resulting in smooth, precise operation and minimal wear. Backlash occurs when the motor driving an actuator reverses its load direction. Since there is a gap between the lifting screw and the worm gear threads, detrimental screw movement may occur. When the actuator is under load, the lifting screws' threads are supported by the worm gears threads. The anti-backlash nut, being pinned by to the worm gear and being adjusted downwards by the shell cap, forces the bottom thread surfaces against the upper thread surfaces of the lifting screw. Thus backlash between the lifting screw and worm gear threads is reduced to a minimum.