A hydrodynamic device located between the engine flexplate and the automatic transmission. It uses transmission fluid to transfer rotational energy from the engine to the transmission input shaft, allowing the engine to idle independently when the vehicle is stopped. At higher speeds, an internal lock-up clutch engages to create a direct mechanical link, eliminating fluid slippage and improving fuel efficiency.
Heard on the job
The transmission fluid smells burnt and the car shudders on acceleration, so the torque converter is likely failing.