Abstract: The disclosure relates to a handling jack for large truck gear boxes, such as third members or the like; the handling jack being adapted to move into position beneath a truck and being provided with a normally vertical column which is adapted to be pivoted on a horizontal axis at a low lever away from a position over the frame of the jack so as to be moveable into position beneath a truck and retractable from a position beneath a truck; and the column member being moveable into vertical position and provided with a handling boom thereon so as to position the handling boom above a truck gear box or third member assembly so as to freely suspend the third member and allow angular freedom of movement thereof for readily removing and replacing the gear box or third member.