Abstract: This self-propelled articulation-steered tractor has a positive adjustment system for controlling the orientation (both elevation and lateral tilt) of a transverse implement mounted on either the front or rear assembly of the tractor, and a reactive adjustment system for allowing terrain-responsive orientation of the axle of the other assembly (front or rear) not carrying the transverse implement. The positive adjustment system is operator controlled. The reactive system may comprise a mounting of the axle for the non-implement-carrying assembly so it freely pivots with respect to the frame of that assembly. An articulation joint transverse swivel pivot system is provided for lateral tilt movement between the front and rear assemblies of the articulation-steered tractor.