Used Mack RD686S Tri Axle Dump Truck for sale. Features: Double Frame, Single Exhaust Stack, Air Ride Cab, 20,000 lb. Page Non-steerable Lift Axle, 17.5 ft. Round Bottom Dump Body w/ Coal Chute, Auto Tarper, Air Lock Tailgate, Stainless Mirrors, Air Conditioning, Heated Body Option, 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).