Abstract: Two wheeled units of a vehicle are adjustably interconnectably positioned relative to each other. An apertured track assembly is stationarily mounted on one of the units, while a locking assembly is mounted on the other of the units. The locking assembly includes at least one locking pin displaceable into and out of at least one aperture on the track assembly. The locking assembly may be unlocked either manually or with power assistance. The two wheeled units may be leading and trailing cargo units of a vehicle whose spacing apart from each other is to be controlled in a load-bearing drawbar arrangement. Alternatively, the wheeled units may be a bogie subframe mounted underneath a cargo unit and movable relative thereto for better weight distribution of the payload in a suspension system.