Outboard Motor Lower Unit Assy
The gearbox is located below the outboard motor head, responsible for transferring power to the propeller and providing a deceleration ratio, because the speed of the internal combustion engine is too high and the torque is not suitable for ship propulsion, so the gearbox is needed to reduce the speed and lift torque, lower unit assy is mainly composed of transmission propeller shaft, outboard gear, and shell.