Is it true that both statements about impeller driving turbine and lock-up 1:1 drive are correct?

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

Answer: (C)

In a torque converter, the pump (impeller) on the engine side pushes transmission fluid toward the turbine, and that fluid flow makes the turbine (linked to the transmission input) rotate. This fluid coupling lets the engine deliver power to the transmission even when their speeds aren’t identical, and at low speeds it also provides torque multiplication because the impeller can spin faster than the turbine. As speed rises, the turbine starts to catch up to the impeller, reducing slip and improving efficiency.

The lock-up mechanism inside many torque converters adds a clutch that, when engaged, directly connects the input and output sides. That creates a 1:1 drive ratio, eliminating slip for steadier, more efficient cruising.

So both statements—the impeller driving the turbine and the lock-up 1:1 drive—are correct.