Camper slide-out system

In a slide-out system to expand and contract the living space of a recreational vehicle by extending and retracting a slide-out room of the vehicle relative to a stationary portion of the vehicle, the slide-out system having a first member that is affixed to the stationary portion of the vehicle, a second member that is affixed to the slide-out room and is slidable relative to the first member, the second member being movable relative to the first member by a pinion that is journalled to the first member and meshes with a rack that is affixed to the second member, the improvement wherein a sliding connection is established between the second member and the first member by a slide block and a mating track, the track being open at one side so as to receive the slide block and the slide block extending into the track through the open side of the track, the slide block being made of a lubricious material that has a form fit with the track, the form fit permitting relative sliding movement between the slide block and the track in the direction of extension and retraction of the room and restraining against relative movement in directions perpendicular to the direction of extension and retraction, the slide block being affixed to one of the members and the track being affixed to the other of the members.