A coupling mechanism controls the location of the central primary draft load transmitting fixed-length link independently of the coupler. The coupling mechanism allows for translation in at least three orthogonal directions and for rotation of two distinct planes between coupled components, thereby providing a means for lateral shifting and articulation. The coupling mechanism mitigates unexpected rotation by restricting rotation along a longitudinal axis of the fixed-length link. Rotation of the coupling mechanism is furthermore controlled by means of a indexing turntable. The orientation and the position of the coupling mechanism is therefore determinant and predictable.