Abstract: A system for controlling a dump truck's tailgate opening may be used when dumping materials out in piles or spreading. The system has a mechanically controlled device that can be mounted to a conventional dump box. A connecting arm is attached to a tailgate which interconnects with a control unit mounted on the dump box. The control unit is configured to catch the tailgate as it falls from a closed position due to the force of gravity. The system allows an operator to select, from within the truck's cab, one or more opening positions for the tailgate.