What is the function of automatic transmission fluid in cars?
2 Answers
Automatic transmission fluid in cars serves as a lubricant to maintain system cleanliness and prolong the lifespan of transmission components. It offers resistance to low temperatures and ensures effective lubrication even in cold conditions, reducing fluid loss under harsh operating conditions. Depending on the transmission structure, transmission fluids are categorized into automatic transmission fluid (ATF) and manual transmission fluid. Approximately 95% of automatic transmission fluids are red in color. Beyond lubricating and cooling the planetary gear set, their primary role is to transmit power. Under normal driving conditions, automatic transmission fluid should typically be replaced every 120,000 kilometers, while under severe driving conditions, replacement is recommended every 60,000 kilometers.
The automatic transmission fluid in my car is a key component that ensures the proper functioning of the transmission. I remember when the transmission noise increased while driving, the mechanic said it was due to the fluid. Automatic transmission fluid primarily serves a lubricating role, reducing friction and preventing excessive wear on internal gears and bearings. It also cools the system by absorbing heat generated during high-speed operation, preventing overheating that could damage the transmission. Additionally, the fluid transmits hydraulic power within the automatic transmission, aiding smooth gear shifts—without it, the car may experience gear sticking or slipping. In terms of cleaning, the fluid helps remove debris and contaminants, protecting components from rust. If not replaced regularly, dirty or degraded fluid can lead to transmission failures, resulting in costly repairs. I recommend checking it every 40,000 kilometers or two years, monitoring the fluid level and color—if it turns from bright red to black, it’s time for a change. In short, though small, automatic transmission fluid is a secret weapon for a car’s longevity.
