A locking assembly and method of securing a dump truck tailgate to a sidewall of the dump truck, and a truck incorporating the same. The locking assembly includes a pressurized pin mechanism mounted on one of tailgate and the sidewall; and a spool mounted on the other of the tailgate and the sidewall. The spool is engageable with the pin mechanism to lock the locking assembly and secure the tailgate to the sidewall, and is disengageable from the pin mechanism to unlock the locking assembly and release the tailgate from its securement to the sidewall. A hinge assembly is provided on an opposite side of the tailgate from the locking assembly. The tailgate is selectively pivotable relative to the truck bed about a vertical axis extending through the hinge assembly or about a horizontal axis extending through both of the locking assembly and the hinge assembly.