This 36645R.S drive screw coupler replacement to replace a stripped screw couplers for garage door openers. Typical symptoms of a stripped Screw Coupler is a grinding noise coming from the rear of the motor head. The motor turns but the screw does not. Remove Coupler and check if it is stripped or has no more threading. The drive screw coupler 36645R.S connects the drive screw to the motor shaft. Unplug the garage door opener before installing this part. Wear work gloves to protect your hands.