This workshop service repair manual provides comprehensive technical guidance for the 480, 500, 540, 580, 640, and 680 DT tractor series. These robust utility tractors, produced in Italy, are known for their reliable diesel engines, ranging from 3 to 4 cylinders and displacements of 2592 cc to 3456 cc, and are designed for a variety of agricultural applications. The DT Series tractors, likely manufactured from the 1970s into the 1980s, are recognized for their solid engineering and dependable performance, making them essential workhorses in their era. This manual covers an extensive range of systems and procedures, including detailed information on engine, powertrain, and chassis components, as well as auxiliary systems like hydraulics and electricals. It offers step-by-step instructions for routine servicing, fluid changes, filter replacements, and in-depth repair procedures for major overhauls. Furthermore, it includes troubleshooting guides and diagnostic procedures to assist owners, mechanics, and technicians in maintaining optimal performance and longevity of their DT Series tractors.