What is the function of automotive transmission fluid?
3 Answers
The function of automotive transmission fluid is to maintain the cleanliness of the gear shifting system, provide lubrication to the transmission components for extended service life, and ensure the normal operation of the transmission. Original equipment manufacturers specify their own dedicated transmission fluids. Generally, automatic transmission fluid should be replaced every 2 years or 40,000 kilometers. Automatic transmission fluid cannot be completely drained using atmospheric pressure - only about half of the used fluid can be removed. The remaining fluid will accumulate with sludge and impurities in the valve body, torque converter, and cooling lines, potentially causing blockages in the internal fluid passages. Regular replacement or maintenance is recommended.
In my years of experience repairing cars, the role of transmission fluid is no small matter. Its primary function is to lubricate all moving metal parts, like gears and bearings, coating them with an oil layer to reduce friction and wear, preventing premature failure. It also helps dissipate heat to prevent the transmission from overheating and damaging components, especially during long-distance drives when temperatures can get quite high—the fluid carries away that heat. Its cleaning properties are equally important, picking up metal shavings and contaminants to keep the internals clean and avoid blockages. In automatic vehicles, it also acts as hydraulic fluid, helping transmit pressure for smooth gear shifts. Additionally, it provides rust and corrosion protection, extending the lifespan of parts. I've seen too many cases where neglecting timely fluid changes led to accumulated issues, ultimately requiring a full transmission rebuild costing thousands. Generally, it's recommended to check and replace the fluid every 20,000 kilometers or two years, using synthetic oil for better durability and fewer headaches. Remember, ignoring it is like letting your heart run without lubrication—sooner or later, the whole system will fail, and the cost of a full replacement will skyrocket. Early maintenance means peace of mind and saves money in the long run.
As an ordinary driver, I have deeply experienced the importance of transmission fluid. Initially, I didn't pay much attention until the gears got stuck, and I realized something was seriously wrong. Its main functions are to lubricate internal components to prevent wear, ensuring smooth and silent gear shifts; its cooling function is crucial to prevent the machine from overheating, especially during high-speed driving; it also cleans the system by removing debris to maintain normal operation. Automatic transmissions also use fluid pressure for gear shifts. Neglecting it can easily lead to complete transmission failure. Last time, my car couldn't shift gears because the fluid had expired, and the major repair cost me 6,000 yuan. Now, during every maintenance session, I urge the technician to check the fluid quality and replace it according to the manual. After switching to high-quality fluid, I noticed better fuel efficiency and longer lifespan. With over 20 years of driving experience, I've learned that small investments prevent big losses. Poor fluid quality also affects overall performance, causing acceleration lag or increased fuel consumption. Changing the fluid early ensures a smoother ride and saves money. Regular maintenance is key—don't wait for problems to arise before regretting it.
