This manual covers International Harvester IH 766, 826, 966, 1026, and 1066 tractors, produced primarily from the late 1960s through the 1970s. These models represent a significant line of medium-duty farm tractors from International Harvester, known for their robust construction, power, and reliability in demanding agricultural applications. They typically feature diesel or LP-Gas engines, manual transmissions often paired with the Torque Amplifier system, and hydraulic power steering. The tractors offer substantial horsepower, ranging from approximately 65 HP to over 100 HP, and are built for significant drawbar pull capacity. Their enduring reputation is built on durability and repairability, making them valuable workhorses for operators and collectors alike.
This comprehensive factory service repair manual provides detailed information for maintaining and repairing your International Harvester tractor. It covers all major mechanical, electrical, and hydraulic systems, including engine overhaul, diesel and LP-Gas fuel systems, cooling, transmission, Torque Amplifier, direction reverser, differential, final drive, hydraulic system, power steering, and PTO. The manual includes step-by-step diagnostic and repair procedures, component overhaul instructions, and routine maintenance guidance. With hundreds of pages of detailed information, illustrations, and technical specifications, this manual is an essential resource for owners, mechanics, and technicians to ensure the proper functioning and longevity of these reliable tractors.
Make:
International Harvester
Models Covered:
766, 826, 966, 1026, 1066
Generations Covered:
Likely represents the primary production runs of these tractor models, typically mid-to-late 1960s through the 1970s.
Common Chassis Codes:
Not explicitly provided, but these models often shared platform elements.
Target Audience:
Owners and operators of IH International Harvester 766, 826, 966, 1026, and 1066 tractors, ranging from DIY enthusiasts to professional mechanics.
Advantage Over Print:
Offers superior convenience and cost-effectiveness compared to traditional paper manuals, with the ability to search, print specific pages, and access on multiple devices.
Content Scope:
Complete official full factory service and repair information, hundreds of pages, detailed illustrations and photos.
Usability:
Easy to use, compatible with all Windows and Mac operating systems, accessible via web browser on any device.
Value Proposition:
Inexpensive way to keep vehicles working properly, saving money on mechanic fees by enabling DIY repairs and maintenance.
Systems Covered Overview:
Comprehensive coverage of all major mechanical, electrical, and hydraulic systems.
Estimated Page Count:
Hundreds of pages (specific count not provided, but implies extensive detail).
Type:
Factory Service Repair Manual / Workshop Manual
Engine Systems:
Includes engine overhaul, diesel fuel system, LP-Gas system, cooling system, governor (non-diesel).
Drivetrain Systems:
Covers transmission overhaul, torque amplifier, direction reverser, differential, final drive.
Hydraulic And Power Systems:
Detailed sections on the hydraulic system, power steering system, and power take-off (PTO).
Braking And Steering:
Includes detailed information on the brake system and steering system.
Chassis And Body:
Covers front system components, belt pulley, and likely other chassis-related elements.
Diagnostic Procedures:
Step-by-step instructions based on complete disassembly, implying troubleshooting and diagnostic capabilities.
Repair Procedures:
Detailed repair procedures for all covered systems, from minor adjustments to major overhauls.
Maintenance Procedures:
Guidance on routine maintenance, service data, and upkeep to keep the tractor in proper working order.
Component Overhaul:
Specific procedures for the complete disassembly and reassembly of major components like the engine and transmission.
Depth:
Complete factory service information, suitable for both DIY enthusiasts and experienced mechanics. Covers everything from basic maintenance to complete rebuilds.
Printability:
Printable - users can print the entire manual or specific pages.
Binding Type:
N/A (Digital PDF format)
Paper Type:
N/A (Digital PDF format)
Engine Types:
Likely covers both naturally aspirated and turbocharged diesel engines. Specific models often used IH D-series or DT-series engines. May also cover LP-Gas variants.
Horsepower Range:
Typically ranges from approximately 65 HP (766) to over 100 HP (1066), depending on the specific model and engine configuration.
Torque Specifications:
Detailed torque specifications for engine components, fasteners, and assemblies would be included.
Fuel Delivery:
Covers diesel fuel injection systems (likely rotary or inline pumps) and LP-Gas fuel systems. Includes carburetor information for non-diesel variants.
Cooling Method:
Water-cooled, with detailed procedures for radiator, fan, water pump, and thermostat service.
Oil Specifications:
Likely specifies API CG-4 or CD rated diesel engine oil, or equivalent. Specific viscosity grades (e.g., 15W-40) would be detailed.
Gearbox Options:
Likely includes manual transmissions, potentially with overdrive options, and often paired with IH's Torque Amplifier (TA) system.
Direction Reverser:
Coverage of the direction reverser option, which allowed for forward and reverse gear changes without clutching.
Torque Amplifier:
Extensive details on the operation, maintenance, and overhaul of the Torque Amplifier (TA), a key feature for on-the-go gear splitting.
Gear Ratios:
Specific gear ratios for all available transmission configurations would be provided for diagnostic and performance analysis.
Transmission Fluid:
Specification of appropriate transmission and hydraulic fluid (e.g., IH Hy-Trans or equivalent) for the gearbox, differential, and hydraulic systems.
Overall Length:
Varies by model; typically around 140-150 inches (without three-point hitch).
Overall Width:
Varies by model and tire configuration; typically around 70-80 inches.
Wheelbase:
Varies by model; typically around 85-90 inches.
Operating Weight:
Typically in the range of 7,000-9,000 lbs (3175-4082 kg) depending on configuration.
Drawbar Pull Capacity:
Significant drawbar pull capability, characteristic of these farm tractors.
Rollover Protection:
While not standard on all units originally, the manual would cover procedures for installing or maintaining aftermarket ROPS (Rollover Protective Structures) if applicable.
Braking System Design:
Serviceable braking systems, likely internal expanding shoe or disc brakes, with detailed repair and adjustment procedures.
Operator Station:
Procedures for seat, controls, and dashboard components relevant to operator safety and comfort.
Operator Interface:
Basic operator interface focused on functionality. Includes instrument cluster with gauges for oil pressure, temperature, fuel level, ammeter, and tachometer.
Power Steering:
Hydraulic power steering system for easier maneuverability, with service procedures detailed in the manual.
Electrical System:
12-volt electrical system powering lights, starter, and accessories. Manual covers wiring diagrams and component testing.
Engine Oil Change:
Typically every 100-250 operating hours, depending on operating conditions and oil type used. Manual will specify exact intervals.
Fuel Filter Replacement:
Recommended at regular intervals, often coinciding with oil changes or specified based on operating hours.
Transmission Fluid Change:
Intervals typically range from 500 to 1000 operating hours for major fluid changes.
Engine Oil Specification:
API CG-4 or CD diesel engine oil, SAE 15W-40 or 30 (depending on ambient temperature). Refer to manual for exact specifications and brands.
Hydraulic Fluid Specification:
IH Hy-Trans (or equivalent multi-functional tractor hydraulic fluid) for transmission, differential, and hydraulic systems. Manual will detail specifications.
Coolant Specification:
Ethylene glycol-based antifreeze mixture (50/50) for protection against freezing and corrosion. Manual will specify type and capacity.
Common Wear Points:
Wear on clutch components, TA clutch packs, hydraulic pump and seals, and differential/final drive bearings are common issues over time. Manual provides repair guidance.
Fuel System Maintenance:
Regular servicing of the diesel injection pump and injectors is crucial for optimal performance and longevity.
Manufacturer:
International Harvester (IH) was a prominent American manufacturer of agricultural machinery, construction equipment, and vehicles.
Series Context:
These tractors represent the evolution of IH's medium-duty farm tractors, succeeding earlier models and incorporating advancements in power, comfort, and features.
Production Period:
Production for these models generally spanned from the late 1960s through the 1970s. For example, the 766 was produced from 1971-1976, the 826 from 1969-1971, the 966 from 1971-1976, the 1026 from 1969-1971, and the 1066 from 1971-1976.
Manufacturing Locations:
Primarily manufactured in the United States by International Harvester.
Industry Standing:
International Harvester tractors of this era were highly regarded for their robust construction, power, and reliability in demanding agricultural environments.
User Reviews:
These models are still sought after by collectors and operators for their durability and repairability, often receiving positive feedback for their workhorse capabilities.
