A disconnect mechanism for a secondary driveline and method of assembly can be used in an all-wheel drive (AWD) vehicle having a rear driveline module (RDM) for changing drive modes between a two-wheel drive mode and an AWD mode. The disconnect mechanism can include a hydraulically actuated coupling clutch connected to a power take-off unit (PTU) for transferring rotary power from the PTU to the RDM during the AWD mode, a hydraulically actuated first and second rear clutch for rotationally connecting and disconnecting corresponding first and second rear axles drivingly coupled to rear wheels during the AWD mode and two-wheel drive mode, respectively, and a hydraulic actuating assembly including a source of pressurized fluid for actuating the coupling clutch, the first rear clutch, and the second rear clutch, and for synchronizing any speed differential therebetween.