A fifth wheel hitch support assembly includes a support bracket adapted to pivotally support a fifth wheel hitch plate, a mounting member adapted to be coupled to a vehicle frame rail to create a gap therebetween and above the frame rail, wherein the gap extends longitudinally along the mounting member, and wherein the mounting member includes a plurality of irregularities spaced longitudinally along the length thereof, and an engagement assembly operably coupled to the support bracket wherein the engagement assembly is operable between an engaged position locking the support bracket with respect to the mounting member at a select position along the length of the mounting member, and a disengaged position wherein the engagement assembly does not engage the plurality of irregularities, thereby allowing the support bracket to be slidably repositioned with respect to the support bracket.