Transmission Fluid

Transmission fluid wears out over time. Because it lubricates one of the most important parts of your car changing it regularly will help your transmission last longer with fewer repairs.

Automatic transmissions have made operating a motor vehicle safe and more convenient.  Drivers no longer need to struggle through gear changes common in “manual” transmissions.

Yet, “automatic” does not mean “maintenance free.”  How can you help keep your vehicle’s automatic transmission operating properly and prevent expensive breakdowns?

Check your owner’s manual or ask your trusted car care professional for recommended service intervals. Your driving habits can influence the mileage between changes (see severe vs. normal driving).

Depending on the condition of your fluid and your mileage the filter (if you have one) may also need to be changed. This service involves removing the transmission pan and replacing the gaskets as well as replacing the fluid.

Fluid used in automatic transmission fluid contains a combination of oil and additives such oxidation compounds, high-temperature thickeners and rust preventatives. Manufacturers design the fluid for specific transmissions and applications.

Tips for getting the most out of your vehicle’s transmission:

-Check with your service advisor or vehicle handbook for recommended service intervals. They vary greatly by vehicle and by driving habits.

-Use manufacturer-recommended automatic transmission fluid. Oil and additives that make up the fluid are designed for specific types of transmissions.

-Exchange the transmission filter when replacing transmission fluid. Metal shavings in an old filter can contaminate the system. (Note: Not all transmissions have filters.)

-Consider how you operate your vehicle. Towing heavy loads in hot environments can break down fluid faster than light loads in mild weather. Ask your service advisor if you need a supplemental transmission cooler if you use your vehicle for towing.

“Heat destroys the additive packages manufacturers include in transmission fluids,” said Tony Molla of the Automotive Service Association. “You can get the best performance out of your automatic transmission through regular fluid replacement and avoid problems when traveling away from home.”

Anthony Belcher, Sensible Driver's Service & Parts Reporter, contributed to this writeup.