A highly refined oil formulated to lubricate gear sets, cool internal components, and provide hydraulic pressure for shifting in automatic gearboxes. It contains friction modifiers, anti-foaming agents, and detergents to prevent wear and sludge buildup. Using the exact specification required by the manufacturer is critical to prevent shift shudder or total failure.
The transmission fluid is burnt and smells like a campfire, so those clutch packs are definitely fried.
Never mix different specifications of transmission fluid; using the wrong friction modifiers will quickly destroy the internal clutches.
Also heard as
- ATF
- gear oil
Related terms
ATF
Automatic transmission fluid is the specialized hydraulic oil used to lubricate and operate gearboxes.
Transmission
The mechanical or hydraulic assembly that adapts engine power to drive the wheels.
Torque converter
A fluid coupling that transfers rotating power from the engine to an automatic transmission.