The International Harvester 1086 is a robust agricultural tractor produced from approximately 1976 to 1981, renowned for its power, versatility, and durability. As part of the successful '86 Series,' it succeeded earlier models and was designed to handle demanding farm work. Available with a range of inline 6-cylinder diesel engines, including the D-358, DT-360, DT-414, and DT-436, it offered substantial horsepower and torque. The 1086 was equipped with either a 16-speed Synchromesh or an optional 16-speed Power Shift transmission, along with features like a 540/1000 RPM Power Take-Off and rear differential lock, making it a capable and reliable machine for its era. This comprehensive Service Repair Manual provides detailed information for all services and repairs, as well as routine maintenance for the International Harvester 1086. It covers extensive troubleshooting, repair, and overhaul procedures for critical systems including the engine, transmission, hydraulics, electrical system, drivetrain, braking, cooling, and fuel systems. The manual also includes guidance on chassis and frame maintenance, diagnostic procedures, and calibration of various components. Designed for mechanics and skilled DIY owners, this manual offers step-by-step instructions, technical specifications, and diagnostic charts to ensure the proper upkeep and repair of the tractor, empowering users to perform maintenance and save on professional service costs.