Abstract: Apparatus for loading and unloading materials onto and from a truck bed includes a corner-mounted swivel hoist mechanism which is releasably clamped to the walls of the truck bed and includes an upper swivel boom member and a lower winch assembly having a cable which can be passed either upwardly over the boom member or rearwardly along the truck bed; and a dump body can be placed on the truck bed and lifted at its front end by the hoist in dumping materials contained in the body. The dump body has an open frame and an inner flexible liner with a rear flap portion of the liner being releasable to an open or lowered position to facilitate removeal of the contents from the body when tilted.