How Often Should Car Gear Oil Be Changed?
2 Answers
Under normal circumstances, gear oil should be changed every 60,000 kilometers. Here is some relevant information: 1. Changing gear oil can effectively improve the efficiency of gear transmission of engine power. The selection of oil viscosity is the most basic factor in choosing gear oil. If the viscosity is too high, it can cause overheating of the friction surfaces and unnecessary power loss. 2. The commonly used steels for manufacturing car gears include tempered steel, quenched steel, carburized and quenched steel, and nitrided steel. The strength of cast steel is slightly lower than that of forged steel and is often used for larger gears; gray cast iron has poorer mechanical properties and can be used in lightly loaded open gear transmissions; ductile iron can partially replace steel in gear manufacturing; plastic gears are mostly used in lightly loaded applications where low noise is required, and the paired gears are usually made of steel with good thermal conductivity.
I drive an old manual transmission car, mainly for commuting in the city. Based on my experience, the gear oil change interval depends mainly on mileage and driving habits. Generally, the owner's manual will provide clear recommendations. For my car, it suggests changing every 40,000 kilometers or 3 years. If you frequently drive uphill, tow heavy loads, or operate in harsh conditions like mountain roads or muddy terrain, you should change it earlier, possibly every 30,000 kilometers. I personally check the oil level and color every six months—normal oil should be light yellow. If it turns black or contains metal particles, it's a sign of gear wear, and you should change the oil immediately. Neglecting this can lead to gear noise, overheating, or even seizing, and repairs will cost much more than an oil change. When buying oil, make sure the viscosity matches the manual specifications, and don’t cheap out on low-quality oil.