The invention provides a roller wheel assembly for sliding patio doors or the like that provides a quick and economical way of installing and retaining the assembly in the door installation. To achieve this result, the assembly employs at least one retaining member that flares outward with respect to the outer surface of the outer housing of the assembly, and at least one mounting tab affixed to an end of the outer housing. Once inserted through a pre-fabricated hole in the lower rail of the patio door, the assembly is retained in its proper location with respect to the door as the material wall thickness of the rail is captured between the retaining member and the mounting tab.