Abstract: Disclosed are methods and apparatus for controllably locking a shaft to a bearing surface moveable thereupon to permit or prevent axial movement of the bearing with respect to the shaft. In one embodiment an axially extending flap is formed in the shaft which is activated by a wedge to expand the diameter of the shaft and thereby lock the shaft to the surrounding bearing surface. In another embodiment a slot is formed in the bushing surrounding the shaft and the internal diameter of the bushing decreased with a wedge screw to lock the bushing to the shaft.