A rotary fluid pressure device (11) includes a plate assembly (17) having a plate member (71) and at least one cover plate (105), which defines a mounting surface (107) adapted for sealing engagement with an exterior surface (77) of the plate member (71), or at least one control valve assembly (105), which defines a mounting surface (117) adapted for sealing engagement with the exterior surface (77). The cover plate assembly (105), when mounted to the exterior surface (77), provides fluid communication between openings (95, 97) of upstream and downstream fluid passages (91, 93), thereby providing single-speed functionality. The control valve assembly (115), when mounted to the exterior surface (77), provides selective fluid communication between the openings (95, 97) of upstream and downstream fluid passages (91, 93), thereby providing multi-speed functionality.