Thanks for your help. I have a sun porch that is probably 30 or more years old made or sold by Patio Enclosures. They are still in business but won't sell me parts last time I called them. The enclosure doors and screens have this wheel assembly. It wears out on the doors. Been swapping roller assemblies between them. But I would like to fix it properly. I have pictures but I do not know how to attach them.