The International Harvester 1066 Tractor, produced from the early to mid-1970s, represents a significant advancement in agricultural machinery. Known for its robust construction and reliable performance, this tractor was a staple on farms, powered by International Harvester's D-358 or D-414 diesel engines. Its design emphasized power and efficiency, making it suitable for a wide range of demanding tasks. The 1066 is celebrated for its role in modernizing farming operations and is recognized for its enduring build quality and operational capabilities, cementing its status as a valuable piece of equipment. This comprehensive service and repair manual provides detailed information essential for the maintenance, diagnosis, and repair of the International Harvester 1066 Tractor. It covers critical systems including the engine, transmission, brakes, hydraulics, cooling, fuel, and electrical systems. The manual offers step-by-step procedures for disassembly, reassembly, overhaul, and troubleshooting, along with technical data and specifications. This resource is designed to empower owners, operators, and mechanics to effectively maintain their tractor, ensuring its longevity and optimal performance.