The _____________ shaft transfers power from the transmission output shaft to the rear axle assembly.

The correct term that fills in the blank is "driveshaft."

The driveshaft is a critical component in a vehicle's drivetrain system. Its primary function is to transmit power from the transmission to the rear axle assembly, enabling the vehicle to move. It is typically a long, cylindrical tube made of materials such as steel or aluminum, designed to withstand the torque generated by the engine and transmission.

In rear-wheel-drive vehicles, the power generated by the engine is first sent to the transmission. From there, it exits through the output shaft and is carried through the driveshaft to the rear axle, where it is ultimately converted into the rotational force necessary to turn the rear wheels. This system relies on universal joints or constant velocity joints to accommodate the relative motion between the transmission and the axle, especially during turns or when the vehicle encounters uneven surfaces.

In summary, the driveshaft plays an essential role in ensuring that power from the engine effectively reaches the wheels, contributing to the overall performance and efficiency of the vehicle.