Torque Converter

📖 YOUCANIC Automotive Glossary

The torque converter is a fluid coupling device that sits between the engine and automatic transmission, transferring engine power to the transmission while also multiplying torque at low speeds and allowing the engine to idle without stalling when the vehicle is stopped. Inside the torque converter is a lockup clutch that mechanically connects the engine and transmission at highway speeds to improve fuel efficiency — this is the component that most commonly fails. A failing torque converter produces a distinct shuddering sensation at light throttle between 40 and 55 mph, slipping or hesitation when accelerating from a stop, overheating transmission fluid, a check engine or transmission warning light with codes related to torque converter clutch performance, and in severe cases a complete loss of drive. Transmission fluid condition plays a major role in torque converter longevity, making regular fluid changes one of the best preventive measures.