Systems and methods for operating a driveline of a hybrid vehicle are described. In one example, a torque that is produced by an engine is adjusted responsive to a transmission oil temperature and a speed of a torque converter impeller so that temperature of oil in a transmission lube circuit may be maintained at a desired temperature.

A drive switching mechanism of a utility vehicle includes: a two-wheel drive and four-wheel drive switching device that switches between two-wheel drive and four-wheel drive of the utility vehicle; and a control unit that controls the drive switching mechanism. The two-wheel drive and four-wheel drive switching device switches between two-wheel drive and four-wheel drive by using a first clutch. The control unit permits the two-wheel drive and four-wheel drive switching device to switch from two- wheel drive to four-wheel drive when a rotation difference of the first clutch becomes equal to or smaller than a predetermined value.

A hybrid drive transmission unit for a vehicle with an internal combustion engine and an electric motor for the drive part, includes a power-split transmission with sub-transmissions and a torsion-damping unit with a gyrating mass interconnected between the internal combustion engine and the power-split transmission. A clutch is interconnected between the internal combustion engine and the torsion-damping unit, by which the internal combustion engine can be activated, switching from the electromotive operating mode.

Methods and systems are provided for operating a powertrain or driveline of a hybrid vehicle that includes two electric machines and a transmission are described. In one example, vehicle propulsion is maintained while transmission operating parameters are determined for improving transmission operation. In particular, a rear drive unit maintains vehicle speed and monitors torque delivered via an output of the transmission.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A slip control method and arrangement for a driveline is described herein. The driveline includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.