The Allis-Chalmers D19 tractor, produced from approximately 1959 to 1962, represents a robust and reliable piece of agricultural machinery. Known for its distinctive orange paint and solid engineering, the D19 was designed as a mid-range workhorse, suitable for row crop farming and general farm operations. It features a 4-cylinder, naturally aspirated diesel engine, typically offering around 65-70 PTO horsepower, coupled with a constant mesh transmission providing eight forward and two reverse gears. Its enduring appeal lies in its straightforward design and the legacy of Allis-Chalmers as a prominent American manufacturer. This comprehensive service and repair manual provides detailed instructions for the maintenance and overhaul of the Allis-Chalmers D19 tractor. It covers all essential systems, including the diesel engine, fuel, cooling, lubrication, transmission, clutch, hydraulic systems, steering, brakes, and electrical components. The manual includes diagnostic procedures, overhaul instructions, maintenance schedules, adjustment specifications, and troubleshooting guides, along with torque values and electrical schematics. Its professional-grade content is designed to assist farm owners, mechanics, and restoration enthusiasts in keeping their D19 tractors in optimal working condition.