The Unique International 2 + 2 Tractors

Published on: 15:42PM Jul 01, 2014

 Written By Larry Gay


On my way home from work one evening in February 1979, I was passed by a semi-truck carrying a strange object as I pulled onto I-80. After catching up to the truck, I saw a "mystery tractor" with four equal-sized wheels, a long red hood, and a cab on the rear before I had to slow for my exit. A few days later, I attended the National Farm Machinery Show in Louisville and there was my "mystery tractor" in the International Harvester display. The sign said it was the new International 2 + 2 tractor.


The unique International 2 + 2 tractor was an articulated, 4-wheel-drive tractor designed to be a row-crop tractor with the operator’s station located on the rear half. The front portion had the engine located ahead of the front axle to provide more weight for the front wheels. The engine compartment was fully enclosed to reduce the noise level. The fuel tank was located in the front portion, behind the engine and front axle. The rear half of the 2 +2 tractor, behind the articulated joint, was essentially the rear portion of the 86 series of 2-wheel-drive tractors.


The International 2 + 2 tractor was introduced as two models. The 3388 was rated at 130 PTO horsepower and the 3588 at 150 PTO horsepower. Both models were powered by 6-cylinder International turbocharged diesel engines with a 436-cubic-inch displacement for the 3388 and 466 cubic inches for the 3588. The Torque Amplifier transmission used a 2-range on-the-go shift with an 8-speed transmission to provide 16 forward speeds. The cab with an integral ROPS was equipped with a heater and air conditioning. The control console to the right side of the deluxe seat contained the hydraulic controls and the one on the left side provided the shift levers for the transmission. The wheels were mounted on bar axles which provided adjustable wheel treads of 60 to 104 inches. The 3-point hitch and independent PTO were standard equipment.


For the 1980 model year, International Harvester expanded its line of 2 +2 tractors with a third model, the 3788. It was rated at 170 PTO horsepower with the 6-cylinder, 466-cubic-inch International turbocharged diesel engine and provided 12 forward speeds. The 88 series of 2-wheel-drive tractors replaced the 86 series for 1982 with new cabs with a right-side control console, lower sound levels, and a choice of interiors. These changes carried over to the 2 + 2 models, along with a new electro-hydraulic brake for easier shifting, and the 3388, 3588, and 3788 became the 6388, 6588, and 6788, respectively. The power ratings remained at 130, 150, and 170 PTO horsepower. At the 1984 fall farm shows, IH introduced two models of the Super 70 series of 2 + 2 tractors. However, these never reached full production due to the purchase of International Harvester’s farm equipment division by Tenneco.


Larry Gay is the author of four tractor books and the "Machinery Milestones" articles in Heritage Iron magazine. To learn more about this magazine which focuses on the 1960-1985 era, go to or call 1-855-old iron.