Target Audience:
Owners and mechanics seeking to maintain, diagnose, and repair the International Harvester Tractor 986.
Manual Value Proposition:
Inexpensive way to keep the tractor working properly; provides detailed illustrations, diagrams, wiring schematics, and specifications; printable pages for workshop use.
Content Focus:
Comprehensive repair and service information, suitable for both do-it-yourselfers and experienced mechanics.
Primary Coverage:
Complete service and repair for International Harvester Tractor 986
Specific Systems Covered:
Engine Mechanical, Engine Electrical, Emission Control, Fuel System, Suspension, Clutch, Manual Transaxle, Automatic Transaxle (if applicable), Driveshaft and Axle, Steering, Brake System, Body Interior and Exterior, Body Electrical System, Restraint System
Estimated Page Count:
Variable (typical workshop manuals for this era can range from 500-1500 pages, depending on detail level)
Type:
Workshop Service Repair Manual / Factory Service Manual
Engine Mechanical:
Detailed overhaul procedures, component testing, specifications, adjustments, torque values for engine assembly (e.g., cylinder head, pistons, crankshaft, camshaft, timing gears).
Engine Electrical:
Wiring diagrams, starter system, charging system (alternator/generator), ignition system, component testing, troubleshooting electrical faults.
Fuel System:
Carburetor or injection system diagnosis, adjustment, repair, fuel pump, fuel filters, fuel lines.
Transmission Clutch:
Clutch operation, adjustment, replacement, hydraulic system, transmission disassembly, reassembly, gear selection, PTO operation.
Hydraulic System:
Hydraulic pump, control valves, cylinders, filters, fluid specifications, troubleshooting hydraulic performance issues, linkage adjustments.
Steering Brakes:
Power steering system diagnosis and repair, brake system components (master cylinder, calipers/drums, lines), bleeding procedures, parking brake adjustment.
Cooling System:
Radiator, thermostat, water pump, coolant specifications, flushing procedures.
Electrical Body:
Lighting system, instrumentation, battery, starter, charging system, wiring harness repair, body panel removal/installation (if applicable).
Maintenance:
Routine maintenance checks, fluid changes, filter replacements, lubrication points, greasing schedules.
Troubleshooting:
System-specific diagnostic flowcharts, symptom-based troubleshooting guides, common problem identification.
Repair:
Step-by-step disassembly and reassembly instructions for all major components and systems.
Overhaul:
Complete engine, transmission, and hydraulic system overhaul procedures.
Diagnostics:
Electrical system diagnostics with detailed wiring diagrams, component testing procedures, resistance and voltage checks.
Depth:
Comprehensive, covering everything from basic maintenance to full engine and transmission rebuilds. Suitable for experienced mechanics and knowledgeable DIY users.
Engine Type:
Diesel (typically 3.1-liter or 4.2-liter variations depending on specific build)
Engine Model Code Example:
DT-360 (3.9L Diesel for some variants, consult manual for exact match)
Horsepower Estimate:
Approximately 70-85 PTO horsepower (varies by specific engine option and tuning)
Torque Estimate:
High torque output suitable for agricultural applications.
Injection Type:
Direct Injection (common for IH diesel engines of this era)
Cooling Method:
Liquid-cooled
Transmission Type Standard:
T-34 (16-speed Power Shift)
Transmission Type Optional:
May have variations or specific regional options.
Powershift Capability:
Yes, the T-34 transmission offers 16 forward and 8 reverse speeds with power shifting capabilities.
Transmission Fluid Type:
IH Hy-Trans Fluid or equivalent (consult manual for specific IH part numbers and approved alternatives)
Engine Oil Change Interval:
Typically every 250 hours or annually (consult manual for precise recommendations based on operating conditions).
Transmission Fluid Change Interval:
Typically every 1000-1200 hours or annually for the powershift transmission.
Engine Oil Specification:
API CD or higher, SAE 15W-40 Diesel Engine Oil recommended (verify with manual for exact viscosity and API service classification).
Hydraulic Fluid Specification:
IH Hy-Trans Fluid or an equivalent universal tractor transmission fluid (UTTF) meeting specific IH specifications. Refer to the manual for precise fluid type and part numbers.
Coolant Specification:
Ethylene Glycol based coolant, typically a 50/50 mix with distilled water. Consult manual for specific type and additives.
Common Wear Points:
Clutch wear, hydraulic pump wear, PTO clutch pack wear, potential for front axle U-joint issues with heavy use, electrical connector corrosion.
Engine Reliability:
Generally robust engines, but like all older diesels, can experience injector issues, glow plug problems, or head gasket leaks if maintenance is neglected.
