The Allis Chalmers D-21 & D-21 Series II Workshop Repair Service Manual is your comprehensive guide to servicing and repairing your tractor. This manual, written by the manufacturer themselves, provides detailed information for both D-21 and D-21 Series II models, covering a wide range of components and systems. Within its pages, you'll find a wealth of technical data, diagrams, and step-by-step instructions to assist you with every repair or maintenance task. Prepare to delve into the intricacies of your tractor with this extensive manual. It covers the engine, lubrication system, cooling system, fuel system, disassembly and servicing procedures, general maintenance, separation process, clutch, transmission, drive chain and sprockets, rear axle, brakes, front axle, steering, shocks, bodywork, intake and exhaust systems, hydraulic system, electrical system, routine maintenance, advanced troubleshooting, and wiring diagrams. This manual is designed to streamline your repair process. It features detailed substeps for enhanced clarity, notes, cautions, and warnings to highlight critical information, numbered instructions for a methodical approach, bold figure numbers for easy reference, detailed illustrations and photos to visually guide you through each procedure, enlarged insets for close-up examination of parts, a numbered table of contents for quick navigation, and combined troubleshooting and electrical service procedures with clear wiring diagrams for simplified electrical system maintenance. Whether you're a seasoned mechanic or a DIY enthusiast, this manual will empower you to tackle repairs confidently and efficiently.

The Allis Chalmers D-21 and D-21 Series II tractors were robust and dependable workhorses designed for a variety of agricultural tasks. Introduced in the 1960s, the D-21 was an evolution of the earlier D-17 model, boasting increased power and improved features. The standard D-21, powered by a 4.4-liter, 4-cylinder, naturally aspirated diesel engine, generated 50 horsepower. It featured a robust 4-speed transmission with a selective gear change mechanism, allowing for smooth and efficient operation. The D-21 was known for its simple design, making it easy to maintain and repair. Later, the D-21 Series II was introduced with several enhancements, including a more powerful 55-horsepower engine, an improved hydraulic system with an increased lift capacity, and a redesigned cab offering enhanced visibility and comfort for the operator. Both the D-21 and D-21 Series II gained a reputation for their work ethic and reliability. They were primarily used for tasks like plowing, disking, mowing, and hauling. Their compact size and maneuverability made them ideal for working in confined spaces, while their durability and strength allowed them to tackle demanding jobs. These tractors were a popular choice for farmers, ranchers, and other agricultural professionals looking for a reliable and versatile machine. While production of the D-21 and D-21 Series II ceased in the early 1970s, these tractors continue to be seen in operation today, demonstrating their lasting legacy of hard work and dependability.