This manual covers John Deere snowmobiles from the 1972 through 1975 model years, encompassing a range of popular models including the 300, 400, 500, 600, JDX4, JDX4 Special, JDX6, JDX8, JD295/S, and JD340/S. John Deere, a company with a long-standing reputation for robust engineering, applied its expertise to these snowmobiles, which represent a significant period of their development in the recreational vehicle market. These machines were designed to offer reliable performance and durability for snow-covered terrains, reflecting the advancements and trends of the era. This comprehensive repair service manual provides detailed information for the repair, service, restoration, maintenance, rebuilding, diagnostics, and troubleshooting of your John Deere snowmobile. It is intended for DIY enthusiasts, home mechanics, professional technicians, and workshops. The manual covers all major systems, including the engine, transmission, chassis, suspension, steering, brakes, and electrical components. It offers step-by-step instructions, clear illustrations, and troubleshooting guides to assist in maintaining and repairing your snowmobile effectively.