This comprehensive Factory Service Repair Manual provides detailed information on servicing and repairing the Allis Chalmers Tractor models D-21, D-21 Series II, 210, and 220. The manual covers a wide range of topics designed to empower you to confidently maintain and troubleshoot your tractor. It includes detailed instructions on diagnosing and resolving common issues, performing routine maintenance tasks, and understanding the intricate workings of your tractor's various systems. Whether you're a seasoned mechanic or a dedicated owner looking to handle repairs yourself, this manual serves as an invaluable resource.

The manual's detailed content includes troubleshooting guides, service procedures, repair instructions, maintenance schedules, wiring diagrams, and more. It provides you with the knowledge and instructions required to carry out a wide range of repairs and maintenance tasks, including engine, transmission, hydraulics, electrical systems, and more.

The Allis-Chalmers Model D-21, produced from 1957 to 1964, stands as a testament to the company's enduring legacy in the agricultural machinery industry. This powerful tractor was a mainstay for many farmers, known for its robust construction, reliable performance, and versatility. The D-21 series featured a 4-cylinder gasoline engine with a displacement of 210 cubic inches, offering a horsepower range of 37 to 45 depending on the model. The D-21 was also available in a Diesel version, the D-210, with a slightly larger engine displacement of 220 cubic inches and a higher horsepower rating of 40 to 50. Additionally, the D-21 series II, introduced in 1960, boasted several enhancements including a redesigned hood, improved visibility, and a more user-friendly operator's platform. These refinements further cemented the D-21's reputation as a well-designed and capable machine.

Beyond power and practicality, the D-21 offered a plethora of features designed to enhance operator comfort and convenience. These included a comfortable and spacious operator's seat, easy-to-use controls, and a well-positioned dashboard offering essential information at a glance. The tractor was also available with a wide range of optional attachments, allowing it to be used for a diverse range of tasks, from plowing and cultivating to hauling and mowing. The D-21's versatility, coupled with its reliability and efficiency, made it a highly sought-after tractor for farmers of all sizes. While production of the D-21 ceased in 1964, its legacy continues to be appreciated among collectors and enthusiasts who recognize its significant contribution to the modernization of agriculture. Many D-21s remain in operational condition, a testament to the robust design and quality of their construction.