This manual covers the Fiat Tractor Series, including models 55-90, 60-90, 70-90, 80-90, 90-90, and 100-90, produced from the early 1980s through the 1990s. These agricultural tractors are known for their robustness and versatility, offering horsepower ranging from 55 to 100 HP. Fiat Tractors, with a significant heritage in agricultural machinery, developed the 90 series to provide increased power, improved operator comfort, and advanced features for a wide array of farming tasks. This series competed with other major manufacturers of the era, offering reliable performance for diverse agricultural needs. The Fiat Tractor Series Workshop Service Repair Manual provides comprehensive, factory-level detail for maintaining and repairing these machines. It covers essential areas including general information, detailed specifications, engine systems (including fuel, cooling, and lubrication), power train, final drive, rear wheels, front axle, steering, electrical systems, and the hydraulic lift unit. The manual includes complete disassembly and reassembly procedures, diagnostic troubleshooting guides, maintenance schedules, torque specifications, and hundreds of illustrations. This resource is designed for farmers, mechanics, and technicians to ensure the longevity and optimal performance of their Fiat tractors.