To provide a power transmission connector capable of arbitrarily controlling a traveling state of a four-wheel drive vehicle.

During the traveling in a four-wheel driving state, though the torque determined by the fluid resistance in passing the oil discharged from a plunger chamber through an orifice 74 is transmitted through the power transmission joint, when a sleeve 78 is slid through a mechanism linked with the operation of a driver, an inclined part 78a of the sleeve 78 presses a head part 78a of a spool 70, the head part 78 is moved left, and the orifice 74 is closed, whereby the fluid resistance is maximized, the torque transmitted by the power transmission joint is further maximized, and a maximum traveling performance can be achieved. When the sleeve 80 is slid in operating an ABS, most of the oil flowing in the orifice flows to a spool 72 side, whereby the torque transmission by the power transmission joint is minimized, and the effect of the ABS is maximized.