Abstract: A slidable adjustable jacking device where the numbers of rotations of a hand crank on a jacking device may be greatly reduced by using a slidable screwjack inner member to re-position a load-carrying member. New in the art is the use of a slidable screwjack inner member and an affixed bar within a tubular outer member and an affixed passageway. This invention re-positions a slidable screwjack inner member to a location and then pins the member such that the member is fixed relative to a trailer. The device is useful for raising or lowering the tongue of a trailer.