Abstract: A viscous coupling is provided in a power transmitting system for transmitting power of an engine to auxiliary driving wheels, and a lock device is provided for locking the viscous coupling so as to directly transmit the power to the auxiliary driving wheels. Driving torque of the engine is detected and compared with a predetermined driving torque and an output signal is produced when the detected driving torque exceeds the predetermined driving torque. An actuator responds to the output signal for operating the lock device to lock the viscous coupling.

Abstract: A transmission system has a main transmission, a sub-transmission, and a transfer clutch for four-wheel drive. The sub-transmission has a reduction gear train for providing a low speed range. A gearshift lever of the main transmission has an ultra-low speed position in a shift pattern. When the gearshift lever is shifted to the ultra-low speed position, a first speed gear of the main transmission and the low speed range of the sub-transmission are selected in response to the operation of the gearshift lever. Further the transfer clutch is engaged, so that ultra-low speed by the four-wheel drive is provided.

Abstract: A device for operating a transmission for a four-wheel drive vehicle, the power transmission system of which is selectively changed to two-wheel driving. The power transmission system selectively provides a two-wheel drive, a high range four-wheel drive and a lower range four-wheel drive via movement of a shift lever. The shift lever has a shift movement pattern which laterally changes direction at an intermediate position, such that the shift lever cannot be shifted from one end position to the other end position without passing the lateral direction change.

Abstract: A manipulation device for a transmission for four-wheel drive motor vehicle comprising a sub-transmission to transmit the power of the engine to a main transmission, a clutch device for selectively connecting or disconnecting the transmission of the output to either the front or rear axle, a shift rail for shifting a clutch in the sub-transmission, an actuating rail, a fixed rail, a shift fork slidably mounted on the actuating rail and on the fixed rail and engaged with the clutch device, and an arm slidably mounted on the actuating rail, shift rail and fixed rail.

Abstract: A transmission includes a planetary gear unit, the carrier of which is connected to an outer race of a one-way brake. A member is constructed of a hub part formed with the inner race of the one-way brake, a cylindrical part splined to a transmission casing and means securing the parts with each other. The cylindrical part is made of the same material as that of the casing.