This comprehensive service and repair manual provides you with all the essential information needed to maintain and repair your 1940-1947 Harley-Davidson Knucklehead motorcycle. It includes detailed work procedures, part numbers, torque specifications, and exploded views, allowing you to perform a wide range of service and repair tasks with confidence. This manual is designed for ease of use, allowing you to access the information you need quickly and effectively. Whether you're a seasoned mechanic or a dedicated enthusiast, this manual is an invaluable resource for keeping your Knucklehead running smoothly.

The Harley-Davidson Knucklehead, produced from 1936 to 1947, stands as a cornerstone in the history of American motorcycles. This iconic motorcycle, known for its distinctive "knuckle" rocker arms, revolutionized performance and design within the industry. The Knucklehead engine, featuring a 45-degree V-twin design, boasted advanced features like overhead valves and a significantly improved lubrication system. The engine's inherent power and smooth running, unheard of in previous models, quickly cemented the Knucklehead as a high-performance machine. The sleek, streamlined design further augmented the bike's appeal, offering exceptional handling and aesthetics that left a lasting impression on riders. Beyond its performance, the Knucklehead represented a shift in Harley-Davidson's identity. This model, coupled with the later Panhead and Shovelhead engines, established the company as a frontrunner in the American motorcycle scene. The Knucklehead's longevity and lasting legacy are attributed to its innovative engineering and enduring style. Despite being discontinued in 1947, the Knucklehead continued to be a popular choice for custom builds and restoration projects. The model has earned a devoted following, with collectors and enthusiasts actively preserving and restoring these legendary machines. Today, Knuckleheads remain a testament to Harley-Davidson's rich history and the company's commitment to pushing the boundaries of motorcycle design and performance.