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A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal.

If you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and the transmission pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels.


As shown in the picture below, there are four major components to a conventional non-lockup torque converter: Front Cover, Turbine, Stator and Pump. Aftermarket bearings in multiple sets, hi-performance sprag assemblies, billet mounting fronts, special steel flame-hardened hubs, component furnace brazing & special surface coatings are some of the steps taken to enhance strength, performance and longevity.

The “Front Cover” of the torque converter is bolted to the flywheel of the engine, so it turns at whatever speed the engine is running at. The fins that make up the “Pump” of the torque converter are attached to the housing, so they also turn at the same speed as the engine. The cutaway above shows how everything is connected inside the torque converter.

The “Pump” of the torque converter is welded to the housing. The pump of a torque converter is a type of centrifugal pump. As it spins, fluid is flung through the fins to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center.


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