The Allis-Chalmers WD Tractor, produced starting around 1947, represents a significant contribution to agricultural mechanization. This robust machine, powered by a 4-cylinder, overhead valve gasoline engine with approximately 201.7 cubic inches of displacement and around 30-35 PTO horsepower, was designed for a wide range of farm tasks. Its engineering emphasizes reliability and practicality, featuring a manual transmission with typically four forward gears and one reverse, a differential lock for enhanced traction, and a functional hydraulic system. The WD's design, characterized by an open operator station and a wheelbase of approximately 80-82 inches, reflects the agricultural technology of its era, offering a dependable workhorse for its intended purpose. This comprehensive factory service repair manual provides in-depth guidance for the Allis-Chalmers WD Tractor, covering all styles. It is designed to assist both do-it-yourself owners and professional mechanics in maintaining and repairing the vehicle. The manual includes detailed engine service, cooling system diagnostics, fuel system maintenance, power train information, and procedures for the clutch, differential lock, electrical system, brakes, and more. With step-by-step instructions, routine maintenance schedules, troubleshooting guides, and hundreds of photos and illustrations, this manual ensures that owners can effectively manage their tractor's upkeep, saving time and expense while preserving its operational integrity.