Recreational vehicle with expansible section

A recreational vehicle having a body including a floor and a side wall having an opening, an extension unit having an outer wall, a top wall, a floor and opposite end walls and shiftable in said body opening between a retracted position with its outer wall substantially flush with said vehicle side wall and an extended position projecting outwardly from said vehicle side wall, means for limiting outward movement of said extension unit, means for sealing said vehicle at said opening in the extended and retracted positions of said extension unit, a plurality of rollers supporting the floor of said extension unit at a plurality of points spaced laterally and longitudinally of the vehicle to accommodate movement between cantilevered extended position and retracted position, and means for guiding movement of said extension unit and preventing downward tilting of the outer part of said unit when in cantilevered extended position, some of said rollers being located adjacent the vehicle side wall to support a central portion of the floor of the extension unit, struts secured to and extending below inner corners of the floor of the extension unit toward said vehicle floor and each journaling a roller, said guide means including tracks carried by the floor of said extension unit engaging the rollers located adjacent to the vehicle side wall and having configurations complementary to the configurations of the rollers engaged thereby.