The Fiat Trattori 480, 480DT, 500 Special, 500 Special DT, 540 Special, 540 Special DT, 640, and 640DT models represent robust and reliable agricultural machinery produced from the late 1960s through the 1980s. These tractors, powered by Fiat 800 Series Diesel Engines, are characterized by their strong low-end torque, manual synchromesh transmissions, and the availability of both two-wheel drive and four-wheel drive configurations. Designed for demanding agricultural applications, they feature a straightforward yet effective mechanical and hydraulic system, including a power take-off (PTO) and a three-point hitch system. Their engineering prioritizes durability and serviceability, making them enduring workhorses in their intended environments. This comprehensive workshop and service repair manual provides essential information for the maintenance, diagnosis, and repair of the Fiat Trattori 480, 480DT, 500 Special, 500 Special DT, 540 Special, 540 Special DT, 640, and 640DT tractors. Covering a wide array of systems including the engine, fuel, transmission, drivetrain, hydraulics, electrical, braking, and steering, this manual details scheduled maintenance, fluid specifications, and common wear items. It offers step-by-step procedures for complex tasks such as engine overhaul and clutch replacement, alongside diagnostic flowcharts and technical specifications. With numerous illustrations, diagrams, and schematics, this 372-page English language manual is an indispensable resource for owners, operators, and technicians seeking to ensure the optimal performance and longevity of their equipment.