A rotating group of a bent-axis axial piston pump/motor is assembled as a subassembly with a removable stabilizing component that holds together and compresses the subassembly while it is outside of the pump/motor case. A yoke that carries a permanent or attachable back plate is installed in the case and positioned aside to allow clearance for installation of the rotating group. After the rotating group is installed, the yoke is moved back into proximity with the barrel, the stabilizing component is removed, and the remaining connections are completed.