[cfree3]

Are you talking about the plastic bearing pad that the entire room rides on?  Or the plastic rail that the ceiling fan assembly slides on when the room goes in and out?

I believe it would be the plastic bearing pad that the entire room rides on. It appears to be failing on the front side of the bedroom slide. It is dragging there which subsequently caused a hole in our seal and we are seeing bits of white nylon type plastic coming from that corner.