USED INTERNATIONAL HARVESTER 1566

This International 1566 tractor is available in Muncy, Pennsylvania, for $17,500 and offers buyers an unusually long seller-reported family ownership history.
The current seller has owned the tractor for approximately two years, following roughly 15 years of ownership by his uncle. According to the seller, the uncle rebuilt the tractor about 13 years ago, and brand-new batteries were installed last winter.
International Harvester produced the 1566 from 1974 through 1976 as a high-horsepower 66 Series row-crop tractor. Published specifications include a 436-cubic-inch DT-436 turbocharged six-cylinder diesel, approximately 183 engine horsepower, a Torque Amplifier transmission, independent 1,000 RPM PTO, and approximately 160 claimed PTO horsepower.
This International 1566 for sale also features a seller-described rubber-and-steel wheel configuration including steel wheels, making it a distinctive option for agricultural buyers searching for an older high-horsepower International tractor.
Available in Muncy, Pennsylvania, this International 1566 tractor is offered at $17,500 with a long seller-reported family history, an approximately 13-year-old rebuild, a steel/mixed wheel configuration, and brand-new batteries installed last winter.
The current seller has owned the tractor for approximately two years, while his uncle owned it for roughly 15 years before him. According to the seller, his uncle rebuilt the tractor approximately 13 years ago. The exact scope of that rebuild has not been itemized, so buyers should verify which major components were rebuilt or repaired.
The exact model year has not yet been confirmed by serial number. International Harvester produced the 1566 from 1974 through 1976 as a high-horsepower 66 Series row-crop tractor. Published specifications list the model with International Harvester's DT-436 turbocharged six-cylinder diesel, a 12-speed Torque Amplifier transmission, two-wheel drive, and approximately 160 claimed PTO horsepower.
International 1566 High-Horsepower Tractor
The International 1566 for sale here represents one of International Harvester's larger conventional row-crop tractors from the final years of the 66 Series.
Published model specifications list the DT-436 engine at 436 cubic inches / 7.1 liters, turbocharged and liquid cooled, with approximately 183 engine horsepower. International Harvester rated PTO output at approximately 160 horsepower, while Nebraska Tractor Test data recorded just over 161 PTO horsepower under test conditions.
The University of Nebraska-Lincoln's historic tractor-test archive identifies Nebraska Tractor Test 1174 specifically for the International 1566 Turbo Diesel. Buyers researching the model can review the official historical test archive for additional background on the tractor's original performance testing. University of Nebraska Test 1174 – International 1566 Turbo Diesel
Seller-Reported Rebuild and Ownership History
One of the most important aspects of this particular 1566 farm tractor is its known family ownership history.
The seller reports that his uncle owned the tractor for approximately 15 years. About 13 years ago, during that ownership period, the uncle rebuilt the tractor. The current seller then acquired it and has owned it for approximately two years.
That gives buyers a substantially better ownership story than a tractor passing through multiple unknown owners, although the exact components addressed during the rebuild should still be confirmed before purchase.
The tractor also received brand-new batteries last winter, providing a recent update to the starting and electrical system.
DT-436 Turbo Diesel Power
The International 1566 was equipped from the factory with International Harvester's DT-436 turbocharged diesel engine.
Published specifications include:

436 cubic inches / approximately 7.1 liters
Six-cylinder diesel
Turbocharged
Liquid cooled
Approximately 183 rated engine horsepower
Approximately 160 claimed PTO horsepower
Approximately 161 PTO horsepower recorded during Nebraska testing

These specifications placed the 1566 firmly into the high-horsepower tractor category of its era.
For buyers wanting additional factory-model information, TractorData's International Harvester 1566 reference provides production, engine, transmission, hydraulic, PTO, dimensional, and serial-number information for the model.
Torque Amplifier Transmission
Published specifications for the International 1566 list a Torque Amplifier two-speed power-shift transmission providing 12 forward and 6 reverse speeds.
This transmission arrangement was a major part of International Harvester's high-horsepower tractor lineup during the period, giving the operator multiple field-working ratios for drawbar and PTO applications.
Buyers should test operation of the transmission and Torque Amplifier during an in-person inspection because the seller has not provided specific information regarding the current transmission condition or whether transmission components were included in the earlier rebuild.
PTO, Hitch and Hydraulic Capability
Published International 1566 specifications list an independent 1,000 RPM rear PTO, along with a Category III/II rear three-point hitch.
The factory hydraulic system is listed as an open-center system with approximately 12 GPM pump flow. Rear and front hydraulic valves were available depending on configuration.
Because hydraulic valve arrangements and other equipment could vary, buyers should verify the hydraulic configuration installed on this particular tractor before matching it to an implement.
Steel and Rubber Wheel Configuration
The seller describes this tractor as having a rubber-and-steel wheel configuration that includes steel wheels.
Because the exact arrangement between the front and rear axles has not been specified, interested buyers should review the current photographs or inspect the tractor to confirm the wheel setup.
This configuration may be particularly relevant to buyers searching for a used International tractor for agricultural operations where steel-wheel equipment is preferred or required.
Published factory specifications commonly reference 11L-15 front and 20.8-38 rear agricultural tires, but those factory pneumatic tire sizes should not be confused with the current seller-reported wheel configuration on this tractor.
Heavy Row-Crop Tractor Platform
Published specifications put the International 1566 at approximately 13,200 pounds shipping weight and around 15,195 pounds operating weight, depending on configuration, with a 105-inch wheelbase.
That size, combined with the DT-436 turbo diesel and high PTO output, made the 1566 suitable for demanding agricultural applications such as:

Heavy tillage
Drawbar work
Large PTO-driven implements
Field preparation
Planting applications when properly matched
Grain-cart and farm hauling applications
General high-horsepower farm work

Suitability for any particular implement should be determined according to PTO horsepower, drawbar requirements, hitch category, hydraulic requirements, ballast, wheel configuration, and field conditions.
A Classic International Tractor With Known Family History
International Harvester built the 1566 from 1974 through 1976 at Rock Island, Illinois. Published records list approximately 7,417 tractors produced, making its production run considerably shorter than many other International models of the period.
For someone specifically searching for an older high-horsepower tractor for sale in Pennsylvania, this machine combines a recognizable International Harvester platform with roughly 17 years of seller-reported ownership history between the current seller and his uncle.
The family history, previous rebuild, recent batteries, and unusual wheel configuration help distinguish this tractor from a 1566 with little or no known background.
Buyers can also browse additional farm equipment for sale through Trustworthy Equipment.
Price and Buyer Information
Asking Price: $17,500
This International Harvester 1566 is located in Muncy, Pennsylvania.
Trustworthy Equipment LLC is marketing this tractor on behalf of the seller and can help connect qualified buyers with the appropriate party.
Serious buyers are encouraged to request current photographs, confirm the exact model year from the tractor's serial number, ask for additional information regarding the prior rebuild, verify the current wheel configuration, and arrange an inspection before purchase.
Financing assistance may be available to qualified buyers through independent financing providers. Approval, rates, terms, and conditions are determined by the financing provider.
Nationwide transportation assistance may also be available through independent transportation providers.
Contact Trustworthy Equipment LLC for current availability or to be connected with the seller.