Most manufacturers recommend replacing transmission fluid every 30,000 to 60,000 miles. If you tow, or do mostly city driving with constant changes of gears, it may be wise to change your ATF even more often. Here's why. Your automatic transmission has a lot of moving parts.

Do you really need to change transmission fluid?

Manual Transmissions: Most vehicle manufacturers recommend a transmission fluid change between every 30,000 to 60,000 miles. The problem is fluid contamination which occurs over time as the synchronizers, bearings and gears in the transmission wear out.

Is it bad to change transmission fluid?

Changing the transmission fluid on a high-mileage car is risky. Don't do it unless your transmission is running fine and the fluid is first-rate, because it can make transmission failure imminent.