1. Iron casting gearbox housing is made of cast iron, which can withstand the high-intensity and high-vibration operation of tractors in farmland. 2. Tractor transmission gearbox housing uses sand casting method, which has high production efficiency and is suitable for the large-scale production needs of tractor gearbox housing. 3. The surface of tractor transmission gearbox housing is machined, and the surface of the housing is smooth.