Automotive Fluid Glossary: ATF

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 The letters stand for “automatic transmission fluid,” though most professionals in the auto business simply use the shorter acronym. ATF is specially blended fluid that is generally thinner than motor oil. It is used to cool the automatic transmission in your vehicle, prevent corrosion inside the transmission, regulate friction in the transmission’s clutches and bands, as a hydraulic fluid to operate valves, and as a fluid coupler inside the transmission’s torque converter. With the operation of a modern automatic transmission being incredibly complex, it’s easy to see why ATF is critical to the trouble-free operation of a transmission. Many modern vehicles use an ATF made from “synthetic” or very highly refined base oils. These fluids are more expensive than ATF used in older vehicles, but they also last longer and require less frequent replacement. 

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The above was written by Garrett McKinnon and was published in the Fall 2011 edition of Vehicle MD