A power unit includes a transmission adapted to transmit rotational power from a crankshaft to a drive axle, with speed change. The transmission has an input shaft rotatably supported on a crankcase. A hydraulic clutch, configured to be selectively engaged and disengaged, is disposed coaxially with the input shaft. A clutch cover covering the hydraulic clutch is connected to the crankcase. A clutch actuator, which controls switching between engagement and disengagement of the hydraulic clutch, and an actuator cover, which covers the clutch actuator in a liquid-tight manner, are mounted to an outer surface of the clutch cover. An oil temperature sensor is mounted to the actuator cover, and is provided for detecting a temperature of oil in an oil chamber, formed between the clutch cover and the actuator cover.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.