Abstract: A three sided spreader box has a pair of columnar members attached to one of its sides. A pair of sleeves slidingly engage the columnar members and allow the spreader box to be coupled to a dump truck having a side delivery conveyor in such a way that the spreader box is held in fixed horizontal relation to the discharge opening of the conveyor but is free to independently move vertically. A road wheel supports the spreader box and provides means for changing the elevation of the bottom edge of the rear wall of the spreader box. Chutework directs asphaltic material from the conveyor into the spreader box. An oiler periodically oils the chute to prevent sticking of the asphaltic material. The rear wall of the spreader may be hinged to allow the inclination from the horizontal of the bottom edge of the rear wall of the spreader box to be varied.