A marine gearbox is a specialized transmission that transfers engine power to a vessel’s propeller, adjusting speed and torque to ensure smooth, efficient propulsion. At General Truck Parts, we carry an extensive selection of Twin Disc and ZF marine gearboxes, trusted worldwide for their precision engineering and proven durability. Our inventory includes models for light-duty pleasure craft, commercial fishing boats, workboats, and offshore applications—covering both current production and legacy units. Whether you need a compact in-line gearbox, a heavy-duty down-angle configuration, or a high-performance QuickShift or MGX series, we supply OEM-quality components designed to keep your vessel operating at peak performance.