Abstract: An adjustable carriage assembly includes a body; a hinge pin disposed in a threaded first bore of the body, the hinge pin having a threaded end and a first longitudinal axis; a lock post disposed in a second bore of the body, the lock post having a second longitudinal axis; a torsion spring disposed around the lock post; and a retention pin disposed in a third bore of the body to retain the lock post in the second bore. A first extension portion of the lock post engages a flat portion of the hinge pin in a locked state. The lock post is operable to rotate about the second longitudinal axis to disengage the first extension portion from the flat portion and place the carrier assembly in an unlocked state so that the hinge pin is free to rotate and move longitudinally within the first bore.