Used Mack GU713 Tri Axle Dump Truck for sale. Features: Heavy Single Frame, Dual Power Steering Boxes, Single Exhaust Stack, 20,000 lb. Hendrickson Non-Steerable Lift Axle, 17.5 ft. x 54 in. Steel Beau-Roc Dump Body, Auto Tarper, Air Tailgate Cylinder, Power Heated Mirrors, Tilt Steering Column, Power Passenger Window, Air Conditioning, Cruise Control, and more. Hundreds of new and used trucks, trailers, and parts for sale at Coopersburg & Liberty Kenworth. Two convenient locations: Coopersburg, PA (near Allentown) and Swedesboro, NJ (near Philadelphia).