The Nuffield Universal Three 3 tractor, manufactured in the United Kingdom during the mid-1960s to early 1970s, represents a robust and reliable piece of agricultural machinery. As part of the esteemed Nuffield Universal range, it was designed with a focus on versatility for farm tasks, durability, and straightforward maintenance. This tractor typically features a 3-cylinder diesel engine, likely in the 30-40 horsepower range, equipped with a direct injection fuel system. Its engineering prioritizes functional operation and longevity, making it a valuable asset for agricultural work and restoration projects. This comprehensive service and repair manual provides essential information for owners, agricultural mechanics, and restoration enthusiasts. It covers a wide array of systems, including detailed procedures for engine and transmission service and repair, brake system maintenance, electrical system troubleshooting with wiring diagrams, and service for the cooling, fuel, hydraulic, and power take-off (PTO) systems. The manual also includes guidance on general maintenance, periodic lubrication, and troubleshooting common wear points and issues. With step-by-step instructions for engine and transmission rebuilds, as well as full tractor overhauls, this manual is an indispensable resource for maintaining the operational integrity and longevity of your Nuffield Universal Three 3 tractor.