The Nuffield Three / Four (3/4) Universal series tractors, manufactured by the Nuffield Organisation in the United Kingdom, represent a significant part of British agricultural machinery history, with production spanning from the mid-1940s into the 1960s. These robust tractors, available in 3-cylinder and 4-cylinder diesel variants, were designed for a wide range of agricultural tasks. Known for their solid engineering and reliability, models like the Nuffield 3DL and 4DM offered dependable performance for farmers and operators. This manual is tailored for Nuffield tractor owners, mechanics, and restoration enthusiasts, providing factory-accurate information to ensure these enduring machines remain operational. This comprehensive factory service repair manual in English offers extensive coverage for the Nuffield Three and Four models, encompassing service, repair, maintenance, and troubleshooting. It delves into detailed procedures for all major systems, including the engine, transmission, hydraulics, electrical components, chassis, and bodywork. Owners and technicians will find step-by-step instructions for routine maintenance, adjustments, and complete overhauls, supported by diagnostic charts, technical specifications, and critical measurements. The manual's well-structured format ensures efficient access to all necessary information, empowering users to maintain and repair their Nuffield tractors effectively.