The gearbox is an important part of the car. Only by keeping it in good working condition can we avoid some problems in the car . Changing the gearbox oil is an important part of the maintenance of the gearbox. Gearbox oil can not only provide lubrication and cleanliness to the entire transmission system, but also achieve heat dissipation and other effects, so that it can protect the gearbox from normal work and extend its service life. Therefore, the oil of the transmission oil must be changed regularly.