Abstract: Embodiments for retaining the spherical ball of a piston connecting rod within a socket in a bore in a drive plate of a bent-axis pump/motor comprise swaging material at the periphery of the socket cavity toward the ball, to an outer diameter such that the swaged region is fully supported against pullout by the cylindrical wall of the bore. Alternatively, a retention ring which is fully supported by the walls of the cylindrical bore retains the ball within the socket and is in turn retained by a snap ring extending into a groove within the bore.