ATF acts as both a lubricant and a hydraulic fluid inside an automatic transmission. It transfers power through the torque converter, activates the valve body to shift gears, and cools internal components. Mechanics rely on its color and smell to diagnose transmission health, as burnt or dark fluid indicates excessive clutch wear.
Grab three quarts of Dexron ATF and top off that Chevy before it leaves the bay.
Fresh ATF is bright red and smells sweet, while burnt fluid turns brown or black and has a harsh, acrid odor.
Also heard as
- automatic transmission fluid
- tranny fluid
Related terms
Automatic transmission
A gearbox that changes gear ratios independently without a manual clutch pedal.
Torque converter
A fluid coupling that transfers rotating power from the engine to an automatic transmission.
Transmission fluid
A specialized hydraulic fluid and lubricant used to operate and protect gearboxes.