A seat adjustment apparatus comprises a first rail (24) and a second rail (26) each having a plurality of openings that extend along a longitudinal axis, the openings being defined by spaced-apart locking surfaces. A locking mechanism having first (56) and second (58) locking portions is configured to engage the first and second rails. The first (56) and second (58) locking portions are selectively rotatable between a released position and a locked position. In the locked position, the first and second locking portions are configured for relative axial movement along the longitudinal axis such that the interaction of the first and second locking portions of the locking mechanism with the spaced-apart locking surfaces of the openings of the first and second rails attenuates longitudinal freeplay therebetween.