Abstract: A self-loading dump body truck comprising a vehicle having a frame, first and second cross members mounted on the frame, the first cross member being positioned near the rear of the vehicle and the second cross member being positioned forwardly of the first cross member, a cargo box pivotally connected to the first cross member and being supported by the second cross member in a lowered positioned, and inverted U-shaped boom member pivotally connected to the first cross member, the cargo box and the boom member having a common pivot axis, a hydraulic cylinder for pivoting the boom member with respect to the frame, a slide connected to the boom member and slidably engaging the cargo box for movement with respect to the cargo box as the boom member is pivoted, and a connecting arrangement for selectively connecting the slide to the cargo box for pivoting the cargo box as the boom member is pivoted.