Red Seal Heavy Duty Equipment Technician Practice Exam

What is the role of a torque converter in an automatic transmission?

1. To synchronize the engine with the wheels

2. To transmit and multiply engine torque to the transmission

3. To act as a brake when needed

4. To monitor engine speed

The correct answer is: To transmit and multiply engine torque to the transmission

The role of a torque converter in an automatic transmission is to transmit and multiply engine torque to the transmission. A torque converter is a fluid coupling that connects the engine to the transmission, allowing the engine to continue running while the vehicle is stationary. It achieves torque multiplication by using a turbine and a stator in a fluid-filled chamber. When the engine runs, the turbine is activated by the engine's output, causing the fluid to circulate and turn the turbine. This process effectively increases the amount of torque that is transmitted to the transmission, providing more power to move the vehicle, especially from a stop or during acceleration. This function is crucial because it enhances the efficiency of the vehicle's power delivery system by allowing for smoother acceleration and better performance under various driving conditions. In contrast, options such as synchronizing the engine with the wheels and monitoring engine speed do not accurately represent the torque converter's primary function, nor does acting as a brake, which involves different components of the braking system.