The International Harvester 826 Tractor, produced approximately between 1969 and 1971, represents a robust and versatile piece of agricultural machinery. As part of the renowned 06/26 series, this tractor is recognized for its power, durability, and significant contribution to farming productivity. Available with D-179 or BD-264 diesel engines, or a C-201 gasoline engine, it offered substantial PTO horsepower suitable for a wide range of farm tasks. Its engineering quality is evident in its solid construction and the availability of various transmission options, including a synchronized manual, a power shift, and a hydrostatic transmission, alongside a 540/1000 RPM PTO. These tractors were built with a focus on reliability and performance, making them a valuable asset for agricultural operations. This comprehensive workshop service manual provides in-depth technical information for the International Harvester 826 Tractor and its variants. It covers all essential systems, including detailed overhaul and troubleshooting procedures for the engine, transmission, driveline, hydraulic system, electrical system, braking system, cooling system, fuel system, and steering system. The manual also includes maintenance schedules, diagnostic trees, repair instructions, and essential technical specifications such as torque values and clearance measurements. Designed for professional technicians, farm owners, and experienced mechanics, this manual is an indispensable resource for maintaining, repairing, and ensuring the longevity of the 826 Tractor, offering manufacturer-approved information to facilitate efficient service and reduce reliance on dealership expertise.