Abstract: The present invention provides a retractable door apparatus for trailer trucks including at least two tracks of extruded aluminum each having at least one guide surface with a wear resistant coating; and a door in slideable engagement to the guide surfaces of each track. The wear resistant coating may include a self fluxing alloy, oxide, carbide, Al bronze alloy, or cermet having a hardness greater than aluminum. The present invention also provides a method of forming the tracks for the sliding or rolling door apparatus including the steps of providing an aluminum extrusion having at least one guide surface with a geometry for accepting a roller bearing or rollers; and forming the wear resistant coating on the guide surfaces at a temperature that does not substantially reduce the mechanical properties of the aluminum extrusion.