The hardenability of gear die forgings is required to be high after heat treatment, and the performance grade is required to be doubled. The application of high-quality equipment for forging and heat treatment and the progress of steel smelting technology provide guarantee for the upgrading of "casting to forging" technology in vehicle manufacturing. In order to meet the requirements of high-speed and heavy-load vehicles such as trucks and reduce the failure rate of vehicles in operation, it is necessary to study the bearing capacity and operation reliability of various components of trucks and vehicles. Reasonable use of high-quality gear die forgings can reduce the heavy load force of motor vehicles.