This workshop repair service manual covers Fiat models 480 DT, 500 DT, 540 DT, and 640 DT. These tractors, produced primarily from the late 1970s through the 1980s, are known for their robust construction and reliability, stemming from Fiat Trattori's long heritage in agricultural machinery. Designed for a wide range of agricultural tasks, these models feature Fiat's dependable diesel engines, typically ranging from 45 to 70 horsepower, paired with manual transmissions and often equipped with four-wheel drive (DT designation). The engineering quality ensures durability and consistent performance in demanding work environments. This comprehensive manual provides detailed information for owners, independent repair shops, agricultural mechanics, and DIY enthusiasts. It covers all engine types, transmissions, and trim levels for the specified models. Within its hundreds of pages, you will find in-depth procedures for engine overhaul, drivetrain repair, chassis system maintenance, and auxiliary systems like hydraulics and electrical components. The manual includes routine and scheduled maintenance, disassembly and reassembly instructions, advanced troubleshooting guides, diagnostic procedures, critical specifications, wiring diagrams, and exploded views, all presented in English with clear illustrations to ensure accurate and efficient upkeep and repair.