The International Harvester 21456 Tractor represents a robust and reliable piece of agricultural machinery, built with the enduring quality for which International Harvester is historically recognized. Designed for demanding farm conditions, this utility tractor embodies the workhorse capabilities that have defined the brand's legacy. Its engineering prioritizes durability and longevity, ensuring optimal performance across a range of agricultural tasks. This model is a testament to IH's pioneering spirit in tractor technology, likely produced during a period of significant advancement in the late 1960s through the early 1980s, making it a valuable asset for any operation. This comprehensive factory service repair manual provides essential information for maintaining and repairing the International Harvester 21456 Tractor. Covering hundreds of pages, it details every aspect of the vehicle, from routine maintenance procedures and fluid specifications to in-depth engine, transmission, and hydraulic system overhauls. The manual includes systematic troubleshooting guides, electrical system diagnostics, chassis and brake service, and power take-off repair. It is an indispensable resource for professional mechanics, dealership technicians, and experienced owners, offering step-by-step instructions, critical torque values, and special tool requirements to ensure the tractor's longevity and peak operational efficiency.