This manual covers the Allis-Chalmers D14, D15, D15 Series II, D17, D17 Series III, and D17 Series IV tractors. These tractors, produced from the mid-1950s through the 1970s, represent a significant era in agricultural machinery, known for their robust engineering and versatility. The D-series tractors were designed to be reliable workhorses, offering a range of engine options including gasoline, LP-Gas, and diesel, and featuring innovative systems like the Power Director transmission and Power Lift hydraulics. This comprehensive documentation ensures that the legacy of these powerful machines can be maintained and their operational capabilities preserved for continued use and appreciation. This workshop service and repair manual provides detailed, in-depth technical information essential for the maintenance and repair of your Allis-Chalmers tractor. It covers all major systems, including engine (diesel, non-diesel, carburetor, LP-GAS), drivetrain (clutch, transmission, final drive), hydraulic and power systems, chassis, and electrical systems. The manual includes step-by-step repair instructions, routine maintenance procedures, troubleshooting guidance, and detailed exploded views with illustrations. This resource is invaluable for owners, mechanics, and technicians seeking to diagnose issues, perform repairs, and ensure the longevity and optimal performance of their D-series tractors.