1973olds98

My back quarter windows have alot of play in them..You can move the window back in fourth pretty easy...I have taken the complete window and mechanic out of the car to see exactly what is wrong...It has 3 nylon parts..One is a roller,,but it looks pretty good..The other 2 ride on the side of the tracks and seem to be where the play is coming from...Does anyone know if these parts are avaible...i see the roller one on ebay but not the other 2,,,thanks