This workshop service manual provides comprehensive repair and maintenance information for Massey Ferguson MF3670, MF3680, and MF3690 tractors. These robust agricultural machines, produced during a period likely spanning the late 1980s through the early 2000s, are known for their reliability and performance in demanding farming environments. The Massey Ferguson brand carries a significant heritage in agricultural machinery, and this series represents a strong offering within their tractor lineup. This manual is designed to cover all essential systems, ensuring that owners and operators can maintain their tractors to the highest standards. The purpose of this manual is to serve as a definitive guide for the upkeep and repair of your Massey Ferguson tractor. It details procedures for engine diagnostics and overhaul, fuel and cooling systems, drivetrain components including the transmission, clutch, axles, and final drives, as well as the electrical system, brakes, hydraulics, and power steering. With hundreds of pages of detailed instructions, illustrations, and diagnostic information, this manual is an indispensable resource for performing routine maintenance, troubleshooting complex issues, and executing complete rebuilds, ultimately helping to preserve the longevity and operational efficiency of your MF3670, MF3680, or MF3690 tractor.