This comprehensive service and repair manual is your ultimate guide to maintaining and repairing your Harley-Davidson Knucklehead motorcycle, covering models from 1940 to 1947. With hundreds of pages of detailed instructions and illustrations, you'll gain a thorough understanding of every nut and bolt on your machine. From routine maintenance like oil changes to more complex tasks like transmission swaps, this manual provides clear, step-by-step guidance to help you tackle any repair confidently. The intuitive search function allows you to quickly find the information you need, and the ability to print specific pages ensures you have the instructions readily available at your workbench. This factory-level manual equips you with the knowledge and expertise of trained technicians, enabling you to make informed decisions about maintaining and repairing your classic Knucklehead, ensuring its continued performance and longevity.

The Harley-Davidson Knucklehead, produced from 1936 to 1947, marked a significant evolution in motorcycle design and cemented Harley-Davidson's dominance in the American market. The Knucklehead, named for the distinctive knuckle-like rocker arm covers on its overhead valve engine, brought significant advancements to the motorcycle world. This iconic engine, with its 45-degree V-twin configuration, was the first mass-produced overhead valve engine in the motorcycle industry. It featured a cast-iron cylinder block, aluminum cylinder heads, and a unique oil-cooled system, contributing to its legendary durability and power. The Knucklehead also introduced a new, more robust frame and a revised suspension system, further enhancing its performance and handling. This 1940-1947 Harley-Davidson Knucklehead Service & Repair Manual provides a comprehensive guide for maintaining and repairing these classic machines. It contains detailed information on every aspect of the motorcycle, from engine and transmission disassembly and reassembly to electrical systems, brakes, and suspension. With clear diagrams, step-by-step instructions, and troubleshooting tips, this manual serves as an invaluable resource for owners, enthusiasts, and professional mechanics. The Knucklehead's engineering innovations and timeless design have made it a highly sought-after classic motorcycle, and this repair manual is essential for preserving these valuable machines and ensuring their continued operation. Owning and maintaining a Knucklehead requires a dedication to meticulous care and precise engineering, and this manual serves as a comprehensive guide to help owners navigate the complexities of their vintage motorcycle.