Abstract: A mechanism is disclosed for controlling the vertical position of the transport trailer floor of a heavy trailer bearing vehicle having a pivoting air spring suspension system such that the transport trailer floor maintains a fixed position level to an adjacent dock platform when parked for loading or unloading. The mechanism comprises various embodiments of a locking system that disables the pivotal movement of selected pivoting suspension elements in any one of a plurality of possible fixed positions such that the transport trailer floor, when parked, resists downwardly imposed forces and maintains a fixed elevation equal to the elevation of an adjacent loading dock platform.

Abstract: A method of welding an axle housing surface to a blank surface includes generated heat in one of the two components. Heat is generated from at least one of these surfaces at their interface sufficient to weld them together. The surfaces are then applied together.