Used Mack GU713 Tri Axle Dump Truck for sale. Features: 17.5 ft. Beau-Roc Body, High-Lift Tailgate, Heavy Single Frame, 20,000 lb. Non-steerable Lift Axle, Electric Flip Tarp, Stainless Sun Visor, Chrome Bumper, Tilt Steering, Heated Power Mirrors with Chrome Covers, Power Passenger Window, Body Vibrator, 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).