How often should the car gearbox oil be changed？

How often should the car gearbox oil be changed？
 

Automotive transmission oil is generally replaced once at 40,000 kilometers, which is what we call magnetic wheel oil.
 

Transmission oil is of great significance for transmission, it can ensure the normal operation of transmission and extend the life of transmission.

DEXRON standard of General Motors and MERCON standard of Ford are representative standards. These two standards give the performance indicators of transmission oil:
 

1, to have appropriate viscosity. Automatic transmission oil is used in a wide range of temperatures between -40 degrees and 170 degrees, and the automatic transmission is very sensitive to the working viscosity of the oil. Different types of transmissions have different viscosity requirements for transmission oil, so automatic transmission cars do not randomly change the type of transmission oil

2, to have good foam resistance. Automatic transmission will produce foam, which will cause great harm to the transmission system. Foam will lead to the torque converter transmission power reduction, serious can make the oil supply interrupted

3, to have good wear resistance. With good wear resistance, to meet the needs of planetary gear transmission, clutch plate work needs.

4, to have good friction characteristics. This ensures smooth shifting, reduces noise and extends life

5, to have good anticorrosion. The joints of the transmission device and cooler are made of copper, so the transmission oil should be good anti-corrosion to ensure that these parts do not rust.