Dismantle the armrest box, remove the buckle, open the cover, remove the two buckles fixed on the gearbox through the shift line, and then remove the two buckles linked with the shift cover. Manual gearbox is mainly composed of gears and shafts, which produce speed change and torque through different gear combinations. Automatic gearbox AT is composed of hydraulic torque converter, planetary gear and hydraulic control system, which realizes variable speed and torque through hydraulic transmission and gear combination. The function of the gearbox is to change the transmission ratio and make the engine work under favorable working conditions.