Final Drive Gearbox is the set of gears at the end of the travel motor that reduces speed and boosts torque before it goes to the sprocket. We mount it between the motor and sprocket, so the motor spins fast but the sprocket turns slower with more power. Inside, a few gears mesh tightly. We fill it with oil and check seals to prevent leaks. If gears show wear, we replace them or seals. Good gearbox means steady tracks and no slipping when pushing loads.