The Allis Chalmers WD45, produced from 1953 to 1957, represents a significant piece of agricultural machinery heritage, succeeding the popular WD model. This tractor, powered by an Allis Chalmers 200 cu in (3.3 L) I4 engine available in diesel or gasoline variants, offered approximately 45 horsepower and was known for its utility and durability. Designed to meet the agricultural safety standards of its era, the WD45 featured a constant mesh manual transmission with typically six forward and two reverse speeds, a single dry plate clutch, and internal expanding shoe brakes. Its robust construction and widespread adoption made it a respected workhorse on farms. This Workshop Service Repair Manual provides comprehensive guidance for the Allis Chalmers WD45. It covers a wide array of systems, including general information, engine mechanical and electrical systems, emission control, fuel, suspension, clutch, manual and automatic transaxle systems, driveshaft and axle, steering, brakes, and body components. The manual details routine maintenance, repair procedures with step-by-step instructions, and diagnostic troubleshooting for common issues. It is an essential resource for do-it-yourself owners and professional mechanics alike, offering detailed illustrations, diagrams, wiring schematics, and specifications to ensure the proper maintenance and repair of the WD45.