China Truck Gears Transmission is used to change the speed and torque from the engine mechanism,it can be fixed or shift to change the output shaft and input shaft transmission ratio,also known as the gearbox. Gearbople : DONGFENG DANA AXLE, ZF BYD, DAIMLER And HOWO.China Truck Gears website:http://www.tractorparts-china.com/truck-gears/