This service repair manual covers a range of Massey Harris tractor models, including the 20, 22, 30, 44, 55, 81, 82, 101, 102, 201, 202, and 203. These tractors, produced primarily from the post-WWII era through the 1950s, represent a significant part of Massey Harris's agricultural machinery offerings. Known for their robust build quality and historical significance, these models catered to diverse farming requirements. The '20' series models were generally smaller utility tractors, while the higher-numbered series and '40'/'50' designations indicated progressively larger and more powerful machines. Massey Harris was a pioneer in agricultural equipment, and these tractors are valued by collectors and operators alike. This comprehensive factory service repair workshop manual provides detailed guidance for maintaining and repairing all models, engines, trims, and transmission types. It covers essential systems including the engine, drivetrain, chassis, and electrical components, with specific procedures for overhaul, maintenance, and troubleshooting. Users will find step-by-step instructions for disassembly and assembly, detailed technical specifications, torque values, and diagnostic charts for common issues. The manual is designed to assist both do-it-yourself owners and experienced mechanics in ensuring the longevity and optimal performance of their Massey Harris tractors, offering an inexpensive and efficient approach to upkeep.