Disclosed is a four-wheel-drive all terrain vehicle capable of smoothly braking wheels in braking operation of rear wheels and having simplified structures of a drive force disconnecting device and a 2WD/4WD switching device. The drive force disconnecting device is provided in a power transmission path for front-wheel-drive, for engagement/disengagement between a cam shaft and an outer race by means of a torque transmission member such as rollers, to allow a driven-side rotary member such as the outer race to become free when a drive-side rotary member such as the cam shaft is braked during 4WD. The rollers are provided between a plurality of cam faces formed on the cam shaft and a cylindrical friction face formed on the outer race, and they are placed in a torque transmission state (4WD) in which the rollers are pressed between the cam faces and the cylindrical friction face or a torque transmission release state in which the rollers are not pressed between them.
展开▼
