The Allis-Chalmers WD, produced from 1948 to 1952, is a robust tractor renowned for its reliability and versatility in agricultural and industrial applications. Built by a significant American manufacturer with a strong legacy, the WD model played a crucial role in the company's success. Its design emphasizes practical engineering, making it a dependable workhorse for demanding tasks. This tractor is equipped with an Allis-Chalmers Model G-156 4-cylinder gasoline engine, displacing 226.2 cubic inches and delivering approximately 35 PTO horsepower, coupled with a 4-speed forward and 1-reverse constant mesh gearbox and an independent PTO. This comprehensive service repair manual provides detailed information for the maintenance and repair of the Allis-Chalmers WD tractor. It covers a wide array of systems, including the engine, fuel, ignition, transmission, rear axle, hydraulics, steering, brakes, and electrical systems. The manual offers step-by-step instructions for disassembly, assembly, repair, and adjustments, along with diagnostic charts for troubleshooting common issues. Designed for professional technicians and experienced DIY mechanics, this manual aims to impart factory-trained knowledge, enabling informed decisions for upkeep and repair, ensuring the continued performance and longevity of the WD tractor.