Target User:
Tractor owners, mechanics, agricultural technicians, and hobbyists seeking to perform maintenance and repairs on the International Harvester 674.
Value Proposition:
Enables cost savings through DIY repairs, provides in-depth technical guidance, and enhances operational knowledge of the tractor.
Manual Benefit:
Facilitates easy, step-by-step repair jobs with detailed instructions, pictures, and wiring diagrams.
Engine Service:
Complete engine overhaul, disassembly, assembly, lubrication, cooling system, fuel system, exhaust system, starting and charging systems.
Transmission Service:
Gearbox overhaul, clutch service, PTO operation and repair, differential service, hydraulic lift system.
Electrical System:
Wiring diagrams, lighting, starting system, charging system, instrumentation, troubleshooting.
Hydraulic System:
Hydraulic pump, control valves, cylinders, external hydraulic circuits, troubleshooting and maintenance.
Front Axle And Steering:
Front axle overhaul, steering mechanism repair, wheel alignment.
Rear Axle And Brake:
Rear axle overhaul, brake system maintenance and repair, parking brake.
Body And Chassis:
Frame, fenders, operator station, ballast, hitches.
Maintenance Procedures:
Routine maintenance, lubrication charts, fluid level checks, filter replacement, greasing points.
Troubleshooting Guide:
Diagnostic procedures for common problems, fault finding charts, specific symptom analysis.
Repair Procedures:
Step-by-step instructions for disassembly, repair, and reassembly of all major components.
Adjustment Procedures:
Valve lash adjustments, brake adjustments, clutch adjustments, hydraulic control adjustments.
Wiring Diagrams:
Detailed electrical schematics for various circuits and options.
Depth Of Coverage:
Comprehensive, covering routine maintenance to full engine and transmission rebuilds, including advanced diagnostics and specialized repairs.
Engine Model Common:
Typically featured engines like the D-179 or D-206 diesel (specific engine may vary by region/configuration).
Horsepower Range:
Approximately 60-70 PTO horsepower (dependent on specific engine variant and configuration).
Injection Type:
Indirect injection (IDI) via distributor-type injection pump (e.g., CAV or Simms).
Oil Specification Example:
API CD or CE rated diesel engine oil, SAE 15W-40 recommended for general use (refer to manual for exact specification).
Coolant Type:
Ethylene glycol-based antifreeze mixture (50/50 with distilled water).
Gearbox Type:
Constant mesh, sliding gear transmission with multiple forward and reverse gears.
Gear Configurations Common:
8 forward speeds and 2 reverse speeds, often with a high/low range selector for a total of 16 forward and 4 reverse gears.
Pto System:
540/1000 RPM Power Take-Off (PTO) with a synchronized drive option.
Differential Lock:
Optional rear differential lock for improved traction.
Transmission Oil Type:
API GL-4 or GL-5 gear oil, SAE 80W-90 recommended (check manual for specific drivetrain requirements).
Wheelbase Approximate:
Approximately 84 inches (2134 mm).
Operating Weight Approximate:
Around 5,000-5,500 lbs (2268-2495 kg), depending on configuration and ballast.
Engine Oil Change:
Typically every 100-250 operating hours, or annually (refer to manual for precise interval based on usage and oil type).
Air Filter Service:
Check daily, clean or replace as needed, typically every 50-100 operating hours depending on dust conditions.
Fuel Filter Replacement:
Replace every 250-500 operating hours or as recommended.
Transmission Oil Change:
Every 1000-1500 operating hours, or every two years.
Hydraulic Oil Type:
Universal Tractor Transmission Oil (UTTO) meeting IH B-6 specification, or a suitable UTF (Universal Tractor Fluid).
Common Wear Points:
Wear in the final drives, clutch wear, hydraulic pump output degradation, and potential seal leaks due to age.
Electrical Corrosion:
Common in older vehicles; wiring harness connectors and grounds can corrode, leading to intermittent electrical faults.
Diesel Injection System:
Injector pump wear or fuel system contamination can affect starting and performance.
Manufacturer Legacy:
International Harvester (IH) was a prominent American manufacturer of agricultural and construction equipment, known for its robust and reliable machinery.
Series Placement:
Part of the 674 series, which succeeded earlier models and represented a refinement in IH's utility tractor line, bridging the gap between smaller utility and larger row-crop tractors.
Production Period:
The 674 was primarily produced in the 1970s, part of the broader range of International Harvester tractors that followed the acquisition of the David Brown tractor line.
