<p>A swivel apparatus includes upper and lower housings having a passage therethrough operably connected with a coupling for selective relative rotation; at least one movable piston having a first position where the housings are rotationally locked to each other and a second position where the housings are free for relative rotation; the piston is retained to the upper housing with a retainer secured within and discrete from the upper housing, and the retainer is axially spaced from a bearing assembly.</p>