7B is an end view of the load-bearing driven gear retainer of FIG. 7A of the leveling device of FIGS. 1A, 1B, or 1C which may be used in lieu of a collar when the leveling device is installed vertically inverted by 180 degrees;FIG. 8 is a side view of another embodiment of the leveling device of the present invention which has a roller disposed at the end of the elevation shaft, and is shown with