Where does maximum torque multiplication occur in a torque converter?

Where does maximum torque multiplication occur in a torque converter?

• A. Technician A
• B. Technician B
• C. Both Technician A and Technician B
• D. Neither Technician A nor Technician B

Answer: (A)

Maximum torque multiplication happens when the turbine is not turning relative to the pump, i.e., at stall. In this stall condition the fluid pumped by the driving element is redirected by the stator back toward the pump, which multiplies the torque transferred to the output. The slip between input and output is greatest here, so the redirection effect is strongest and the torque boost is largest. As the turbine begins to spin and slip decreases, the multiplication effect diminishes. Once the torque converter’s lock-up clutch engages, the multiplication effectively disappears and the system behaves like a direct 1:1 drive.