Transmission Fluid Flush
A transmission fluid flush is best left to an auto mechanic equipped with a transmission flusher, like a BG PF5. This replaces the fluid more thoroughly than you could achieve with gravity alone.
Understanding Transmission Fluid
Transmission fluid is a slippery liquid that acts as a lubricant for all of the moving parts inside your transmission. In an automatic transmission, this fluid also serves as a coolant and transmits power from the engine to the transmission.
A variety of fluids are used for different transmissions. Your owner's manual will tell you what your transmission calls for.
Transmission Fluid Flush Is Important
Transmission fluid needs to be flushed and changed regardless of whether you have a manual or an automatic transmission.
- Manual transmissions: Most manufacturers recommend that manual transmission fluid be changed every 30,000 to 60,000 miles. Under heavy use, some manufacturers suggest changing transmission fluid every 15,000 miles.
- Automatic transmissions: Service intervals vary from every 30,000 miles to never. The typical service interval is 60,000 to 100,000 miles. Changing it more often does no harm.
Why Flush Your Transmission Fluid
In a manual transmission, transmission fluid contamination occurs over time as the synchronizers, bearings, and gears in the transmission wear out. Metal particles then float around in the lubricant. If these contaminants are not drained out with a transmission fluid flush, they will shorten the life of your transmission.
In the case of automatic transmissions, more heat is generated and the fluid actually breaks down with use. Automatic transmission fluid becomes contaminated with worn bits of the transmission. If these contaminants are not drained out, they will shorten the life of your transmission.
If you don't do a transmission fluid flush on schedule, any contaminants will shorten the transmission's life. Change the transmission fluid at the correct interval to preserve the health of your transmission.
Check Your Transmission Fluid
Automakers use color-code dipsticks. The red ring is for the automatic transmission fluid. The yellow ring checks the engine oil.
Regularly check the transmission fluid level between service intervals. Don't let your car run low on transmission fluid.
Here's how to check your transmission fluid level:
- Manual: A few manufacturers have included a dipstick, but that's the exception rather than the rule. If you own a car with a manual transmission, ask your auto mechanic to check the fluid level when your car is up on the lift during an oil change. It takes just a minute.
- Automatic: Cars with automatic transmissions have a dipstick for this purpose. Pull the transmission dipstick out while the engine is warmed up and running and with the transmission in park. Check your owner's manual, however, since some manufacturers may have a different procedure.