The Milwaukee 14-29-0038 Gearbox Assembly helps transfer and control rotational power within compatible power tools during operation. Designed as a replacement gearbox assembly, it works with the tool’s motor to transmit power through the internal gears and drive the connected components at the required speed and torque. A properly functioning gearbox can support smooth power transfer... https://www.wholetoolbox.com/milwaukee-14-29-0038-gearbox-assembly/14-29-0038.html