How Often Should Gear Oil Be Changed?
2 Answers
Under normal driving conditions, vehicle gear oil should generally be changed every 120,000 kilometers, while under poor driving conditions, it should be changed every 60,000 kilometers. The role of gear oil: The main function of gear oil is to keep the shifting system clean, lubricate, and prolong the life of the transmission device. Due to different transmission designs, which are divided into manual transmissions and automatic transmissions (also including CVT, AMT, etc.), each transmission design has different technical requirements. Even the same type of transmission configuration in different models varies in torque, weight, speed, structure, etc. Therefore, the original manufacturer specifies its own dedicated transmission oil. Usage scenarios for three types of gear oil: For ordinary car gears, choose ordinary car gear oil; if the car is driven in a very poor environment, frequently bumping on mountain roads, the use of hypoid gear oil can be considered; if the vehicle has hypoid gears, then hypoid gear oil must be used. Amount of gear oil used: Since gear loads are generally above 490 MPa, and hypoid gear surface loads can reach up to 2,942 MPa, the amount of gear oil accounts for about 6-8% of the total lubricating oil. Base oils commonly used to blend gear oil include 500SN, 650SN, 150BS, 200BS, etc. Some also use synthetic oils such as PAO, polyethers, etc. Generally, GL-4, GL-5 grades of 85W/90, 85W/140, and 90, 140 oils can be blended with ordinary mineral oils, while GL-4, GL-5 grades of 75W/90, 80W/90 require blending with synthetic oils.
The frequency of gear oil changes depends on the specific vehicle condition and individual driving habits. Based on my experience, most manual transmission vehicles are recommended to change the oil every 50,000 kilometers or every two to three years, while automatic transmissions may require more frequent changes, such as around every 40,000 kilometers. The key factor is driving habits; if you frequently drive in congested city traffic with constant gear shifting, it accelerates oil degradation, and I suggest checking it every 30,000 kilometers. Extreme climates also have an impact—cold winter temperatures can thicken the oil, while high summer temperatures cause it to thin more quickly. Regularly inspect the oil's color and condition; if it appears black, cloudy, or contains metal particles, it's time for a change. Don’t skimp on this small expense—poor-quality gear oil can lead to increased transmission wear, and long-term neglect may result in costly repairs. I’ve personally seen a friend spend tens of thousands on a major transmission overhaul due to ignoring this.
