This jeep can be extended to create a second axle group for the truck. In the collapsed position, the jeep is pinned onto the truck and acts like a third axle. When it is extended, the jeep is only pinned by the king pin and acts like a jeep. In the extended position, 96 inches of inter-axle spacing is attainable by moving the fifth wheel backwards by 11 inches. The fifth wheel is at a fixed distance from the king pin. This fixed position is a compromise between the loading ratio when closed and opened. The fold-away landing gear at the front will straddle the truck when it is being uncoupled. needed