Abstract: A jack assembly for altering the height of an object such a recreational vehicle. The jack includes an outer tube secured to the vehicle and an inner tube having a ground engaging portion and telescopingly received within the outer tube. An axial screw operably connected to a crank at the top of the jack extends through the tubes for altering the length of the jack. The screw threadably engages a screw nut mounted within the inner tube. In order to reduce the material volume of the screw nut, the nut is positionally captured within a retainer seated within the lower tube The retainer is configured to seat within the upper end of the lower tube and includes a slot for receiving the screw nut. The nut and the retainer include corresponding flats to prevent rotation of the nut within the retainer.

Abstract: A jack assembly for raising and lowering an object such as a trailer. The jack includes telescoping jack tubes which are expanded and contracted through operation of an axial screw. The screw is drivably connected to a gear drive mounted in an upper end of the jack. A crankshaft is supported within the upper end of the jack tube by a pair of end bushings and includes a hexagonal intermediate portion. A first pinion gear having a hexagonal throughbore is drivably mounted to the intermediate portion of the crankshaft. The first gear is in driving engagement with a screw gear connected to the axial screw. At least one of the end bushings is removable to facilitate disassembly of the gear drive. Rotation of the crank transmits rotation to the crankshaft and the first pinion gear in turn transmitting rotation to the screw gear and the axial screw for telescoping movement of the jack.