How often should AT transmission fluid be changed?
2 Answers
AT transmission fluid should be changed approximately every 89,000 kilometers. The details are as follows: 1. Because the transmission operates in a high-temperature environment for a long time, it will cause faster wear and tear of components and even damage. Generally, it is recommended to change the fluid every 80,000 kilometers; 2. If the transmission fluid cannot be completely drained, use atmospheric pressure cleaning to remove about half of the waste fluid. Residual fluid may contain sludge, impurities, etc., which can accumulate in the valve body, torque converter, and cooling lines, causing blockages in the internal oil passages; 3. Over 99% of transmission failures are caused by overheating and prolonged failure to change AT fluid, leading to the appearance of impurities. It is also necessary to check whether the transmission pan is deformed or if there are any oil leaks in the transmission lines.
I run an auto repair shop and deal with customers asking about transmission fluid every day. For regular automatic transmission cars, changing the fluid every 60,000-80,000 km is generally safe, but don't just rely on mileage! Pay attention to three key points: older vehicles should have their fluid quality checked at 40,000 km, frequent stop-and-go traffic calls for earlier changes, and the manufacturer's manual is the golden standard. Last week, a BMW's valve body seized up because the fluid wasn't changed until 120,000 km – the repair cost was enough for two fluid changes. Remember, healthy fluid is light red and transparent; if it turns soy-sauce colored with a burnt smell, change it immediately! I recommend replacing the filter along with the fluid during changes – this can extend the service life by two years compared to changing the fluid alone.
