The Allis-Chalmers Model B Tractor, produced from 1937 to 1957, represents a significant chapter in agricultural history. Known for its affordability, reliability, and versatility, the Model B was a highly successful light farm tractor, with hundreds of thousands manufactured. Its robust design and practical utility made it a staple on farms for decades. This tractor is powered by a gasoline, 4-cylinder L-head engine, typically manufactured by Waukesha, with a displacement of approximately 125 cubic inches and rated at 20-25 PTO horsepower. Its transmission features four forward gears and one reverse gear, coupled with a single-plate dry-type clutch. The Model B's engineering quality and enduring legacy are a testament to Allis-Chalmers' prominence as a manufacturer of agricultural and industrial equipment. This comprehensive workshop service and repair manual provides detailed information for the Allis-Chalmers Model B Tractor. It covers a wide array of systems, including the engine, fuel, ignition, cooling, lubrication, transmission, rear axle, hydraulic system (if equipped), power take-off, braking, steering, electrical, chassis, and bodywork. The manual includes step-by-step procedures for engine overhauls, transmission repairs, component rebuilds, and adjustment procedures for critical systems. It also features troubleshooting guides, preventative maintenance schedules, and detailed technical specifications. Written by the original manufacturer, this English-language manual is designed for professional technicians, farm equipment mechanics, restoration specialists, and dedicated DIY owners, ensuring accuracy and completeness for effective maintenance and repair.