POWER TRANSMISSION DEVICE FOR FOUR-WHEEL DRIVE VEHICLE

PROBLEM TO BE SOLVED: To provide a power transmission device for a four-wheel drive vehicle that can reduce drag torque while improving torque transmission responsiveness toward secondary drive wheels side.SOLUTION: The power transmission device 100 positioned between a propeller shaft 16 at a front wheels 14 side and a drive pinion shaft 21 at a rear wheels 19 side includes: a coupling unit 110 that can be switched between an engagement state where torque input from the propeller shaft 16 is transmitted to the drive pinion shaft 21 due to engagement torque of a multiplate wet clutch and a release state where the torque is not transmitted; a diff-lock unit 120 that can be switched between a connected state where the propeller shaft 16 is connected directly with the drive pinion shaft 21 and a non-connected state where the torque is not transmitted wherein a common actuator 130 performs switching between the engagement state and the release state at the coupling unit 110, and between the connected state and the non-connected state at the diff-lock unit 120.