PURPOSE:To eliminate the need of reoperating a differential locking device (diff-lock device) and simplify operation by enabling operation of a differential gear or locking differential rotation with the differential gear by connecting or disconnecting a pair of petals. CONSTITUTION:A differential gear 8 divides rotation power from an engine and transmits the power to left and right back wheels 4. A diff-lock device 30 prevents the differential rotation of the differential gear 8. Further, a pair of side clutches 22 connect the rotation power transmitted from the differential gear 8 to the left and right back wheels 4. A pair of petals 32 and 32' operate the side clutches 22. When the aforementioned pair of petals 32 and 32' are connected so as to simultaneously operate, the differential gear 8 is operated so that the left and right back wheels 4 may perform differential rotation. When the aforementioned connection is severed so as to provide individual operation, the diff-lock device 30 prevents the operation of the differential gear 8 and connects to the device 30 so that the let and right back wheels 4 may rotate at a uniform velocity. As a result, reopration of the diff-lock device is not required to simplify the operation.
