When a World Transmission (WT) is in reverse, the input power from the engine enters the gear train through which of the following?

When a World Transmission (WT) is in reverse, the input power from the engine enters the gear train through which of the following?

• A. P-2 and P-3 sun gears
• B. P-1 carrier
• C. P-1 sun gear
• D. P-2 carrier

Answer: (C)

When the WT is in reverse, the engine’s torque is applied to the first planetary gear set through its sun gear. Driving the P-1 sun gear makes the planet gears rotate in a way that, with the other gear sets clutched into the reverse pathway, the output shaft ends up rotating in the opposite direction. The sun gear is the central input element for that stage, so powering through it is what reverses the overall drive. If power were to enter through other members, the gear train wouldn’t produce the correct reverse motion due to how the clutches connect the sets in reverse.

When the WT is in reverse, the engine’s torque is applied to the first planetary gear set through its sun gear. Driving the P-1 sun gear makes the planet gears rotate in a way that, with the other gear sets clutched into the reverse pathway, the output shaft ends up rotating in the opposite direction. The sun gear is the central input element for that stage, so powering through it is what reverses the overall drive. If power were to enter through other members, the gear train wouldn’t produce the correct reverse motion due to how the clutches connect the sets in reverse.