The International Harvester 424 tractor, produced from the mid-1960s to the early 1970s, represents a robust and reliable utility tractor from a manufacturer with a significant legacy in agricultural and construction equipment. Designed for a wide array of farm tasks, this model typically features a Continental engine, available in diesel or gasoline variants, with displacements commonly ranging from 3 to 4 liters, delivering approximately 40-60 PTO horsepower. Its engineering prioritizes durability and functionality, making it a dependable workhorse for its intended purpose. The 424 is equipped with a manual constant mesh gearbox, often offering 8-speed forward and 2-speed reverse configurations, and utilizes a dry, single-stage clutch. Its operational weight is around 4,000 to 5,000 lbs, with a wheelbase of approximately 75-80 inches, contributing to its stable performance in various field conditions. This Workshop Service Manual (WSM) provides comprehensive coverage for the International Harvester 424 tractor, serving as an essential resource for owners, mechanics, and DIY enthusiasts. The manual details routine maintenance procedures, including lubrication schedules, filter replacement, and fluid level checks, alongside in-depth repair and overhaul instructions for engine, powertrain, chassis, and electrical systems. It also offers step-by-step diagnostic and troubleshooting guides for common issues, supported by detailed diagrams and pictures. Specific sections address engine systems, clutch, transmission, differential, PTO, steering, braking, hydraulics, and electrical components, ensuring users have the technical knowledge to maintain and repair their tractor effectively, saving time and money on service.