Abstract: A drive assembly for a lifting the top of a mobile housing includes a first and second pairs of push-pull springs. The springs are connected to an drive assembly and to the top. The drive assembly includes a threaded shaft having a threaded block which travels thereon and a cable associated therewith. When the threaded shaft is rotated, the push-pull springs move. A pulley structure is provided for allowing adjustment of the position of the first pair of springs relative to the second pair of springs.