Used Mack GU713 Tri Axle Dump Truck for sale. Features: Single Frame, Air Ride Cab, Dual Power Steering Boxes, 20,000 lb. Hendrickson Non-steerable Lift Axle, 17.5 ft. x 54 in. J&J Steel Dump Body, Auto Tarper, Air Tailgate Lock, Power Heated Mirrors, Power Locks and Windows, Tilt Steering Column, Air Conditioning, Cruise Control, Disc Brakes, and more. Coopersburg & Liberty Kenworth has new trucks, used trucks, trailers, and parts for sale. Locations: Coopersburg, PA (near Allentown), Swedesboro, NJ (near Philadelphia), and TRP 068 (Pottstown, PA).