of the center hole 86 of the front bearing plate 80 through which the output of the rotor 120 is directed and should be just slightly larger in width than the pins 94 such that a sliding fit between the two is established further the pins 94 and the corresponding radial slots 82 should be disposed 180 u00b0 apart in this way the reaction force on the cylinder casing 90 acts against two points that are symmetrically disposed about the axis of the cylinder casing 90 rather than one thus the skewing effect of a single point force application is avoided further the cylinder casing 90 is allowed move with limited relative movement with respect to the front bearing plate 80 at least generally along the plane of the slots 82 this action may be referred to as floating the floating allows the cylinder casing 90 to at least partially self center about the rotor 120 in another aspect of the present invention alone or in combination with the u201c floating u201d rotationally moveable cylinder casing 90 the approach of the present invention utilizes a moveable front bearing plate 80 to help select between forward and reverse the front bearing plate 80 is positioned within the housing 20 such that it is.