A drive assembly for a slide out in an expandable enclosure, the drive assembly comprising a beam attachable to the slide out, the beam having a first row of teeth and a second row of teeth thereon, the first row of teeth and the second row of teeth extending parallel to each other on opposite sides of the beam wherein the teeth in the first row of teeth are offset relative to the teeth in the second row of teeth and a drive gear having a first gear wheel engagable with the first row of teeth and a second gear wheel engagable with the second row of teeth, and an actuator coupled to the beam to selectively extend and retract the beam.

An apparatus for moving a slide-out room disposed in an aperture of a side wall of a vehicle from a retracted position to an extended position in a drive direction. The apparatus includes a drive assembly supported by the side wall of the vehicle and a driven assembly driven by the drive assembly. The driven assembly is connected to a wall of the slide-out room such that the slide-out room moves with the driven assembly from the retracted position to the extended position in the drive direction and the driven assembly is movable in a transverse direction generally perpendicular to the drive direction relative to the wall of the slide-out room.