Target Audience:
Owners, mechanics, and technicians specializing in or maintaining vintage International Harvester agricultural tractors.
Value Proposition:
Provides essential technical information and service updates crucial for maintaining older, often high-value, vintage tractors where original documentation might be scarce or incomplete.
Key Manual Features:
Compiled service bulletins offer targeted solutions and updates, acting as a supplement to standard workshop manuals for enhanced repair and maintenance capabilities.
Covered Models:
All International 634 Vintage Series Tractors
Applicable Variants:
All configurations of the 634 series tractors, including different engine options or feature packages as detailed in the bulletins.
Manual Type:
Service Bulletin Compilation / Workshop Supplement
Manual Supplementary Nature:
This is a compilation of Service Bulletins, acting as critical addenda or updates to the original Workshop Manual, addressing specific technical changes, fixes, and known issues identified during the tractor's service life.
Format:
Digital Download (PDF implied)
Engine Systems:
Engine overhaul, fuel system, lubrication, cooling system, starting and charging systems, component diagnostics
Drivetrain Systems:
Clutch, transmission (gearbox), differential, final drives, Power Take-Off (PTO) systems
Hydraulic Systems:
Hydraulic pump, control valves, lift cover assembly, auxiliary hydraulics (if applicable), hydraulic fluid specifications
Chassis Steering Braking:
Front axle, steering system (mechanical/power assisted), braking system (mechanical/hydraulic), wheel alignment
Electrical Systems:
Wiring diagrams, lighting, instrument panel, starter motor, generator/alternator, battery maintenance
Operator Station:
Seat, controls, dashboard layout, safety features
Front Axle Steering:
Inspection, adjustment, and repair of front axle components, steering linkages, and steering box.
Maintenance Procedures:
Routine servicing, lubrication schedules, filter changes, fluid top-offs, belt adjustments, tune-up procedures
Repair Procedures:
Component removal and installation, engine rebuilding, transmission overhaul, hydraulic system repair, brake system service
Troubleshooting:
Diagnostic charts, common problem identification, corrective actions for various system malfunctions
Overhaul Instructions:
Detailed instructions for complete engine, transmission, and hydraulic system overhauls, including component specifications and assembly sequence.
Calibration Procedures:
Potentially includes calibration for specific hydraulic components or PTO settings if addressed in bulletins.
Depth Of Coverage:
Comprehensive workshop-level technical data, including detailed disassembly and assembly instructions, torque specifications, clearances, and diagnostic routines.
Bulletin Format Advantage:
Service bulletins often provide specific updates, modifications, and solutions to known issues or design improvements not always present in original workshop manuals.
Diagnostic Charts Availability:
Likely includes diagnostic flowcharts and symptom-cause-remedy tables for common operational faults.
Wiring Diagrams:
Comprehensive electrical system schematics and troubleshooting guidance for all onboard electrical components.
Engine Family:
International Harvester BD Series (likely BD-154, BD-206, or BD-239, depending on specific 634 variants)
Engine Type:
Direct injection, naturally aspirated, diesel engine.
Bore Stroke Examples:
BD-154: 3.5" x 4.25", BD-206: 3.75" x 4.25", BD-239: 3.875" x 4.375" (Approximate, specific to engine variant)
Horsepower Range:
Typically 40-65 PTO horsepower, depending on engine displacement and configuration.
Compression Ratio:
Typically around 16.5:1 to 18:1. (Specific to engine model).
Injection System:
Typically CAV or Simms inline fuel injection pump.
Governor Type:
Mechanical centrifugal governor.
Oil Type Recommendation:
API CD or CE rated diesel engine oil, SAE 15W-40 or 20W-50 depending on ambient temperature. (Consult specific bulletin for exact specs).
Transmission Type:
Constant mesh gearbox with synchronized or unsynchronized gears. Likely a 6-speed or 8-speed forward transmission.
Additional Options:
Possible options include a Hi-Lo transmission (e.g., Torque Amplifier) or creep speed gearbox for specialized applications.
Pto System:
Standard 540 RPM PTO, potentially with an option for 1000 RPM PTO. PTO engagement is usually manual.
Transmission Fluid Type:
Universal Tractor Transmission Oil (UTTO) or equivalent. (Consult specific manual for exact specification, e.g., John Deere J20C or equivalent).
Rear Axle Type:
Heavy-duty planetary or spur gear final drive reduction.
Wheelbase:
Approx. 80-85 inches (2032-2159 mm) for standard 2WD configuration.
Track Width Front:
Adjustable, typically 50-64 inches (1270-1626 mm).
Track Width Rear:
Adjustable, typically 54-72 inches (1372-1829 mm).
Operating Weight:
Approx. 4,500 - 5,500 lbs (2041 - 2495 kg) without ballast.
Engine Oil Change Interval:
Typically every 100-250 operating hours or annually, whichever comes first. (Specifics in manual).
Fuel Filter Replacement:
Recommended at 250-500 operating hours or as needed based on fuel quality. (Specifics in manual).
Hydraulic Fluid Change:
Generally every 1000-1200 operating hours or if contamination is suspected.
Hydraulic Fluid Spec:
IH Hy-Trans fluid or equivalent UTTO. Capacity approx. 9-10 gallons. (Consult manual for exact capacity and specification).
Coolant Specifications:
Ethylene glycol based antifreeze mixed with distilled water at a 50/50 ratio for freeze protection and corrosion inhibition.
Engine Oil Capacity:
Approx. 5-7 quarts (4.7-6.6 liters) including filter. (Consult manual).
Transmission Oil Capacity:
Approx. 10-12 gallons (38-45 liters) for the combined transmission, hydraulic, and final drive reservoir. (Consult manual).
Common Wear Points:
Clutch wear, PTO clutch/brake wear, hydraulic pump and cylinder seal degradation, steering system wear, starter motor and generator issues, potential fuel injector problems.
Electrical System Concerns:
Corrosion in connectors, aging wiring harnesses, intermittent issues with lighting and instrumentation due to age.
Steering System Wear:
Kingpin bushings, tie rod ends, and steering box wear are common in high-hour units.
Manufacturer Heritage:
International Harvester (IH) was a major American manufacturer of agricultural machinery, trucks, and construction equipment, known for robust and reliable products.
Series Context:
The 634 series represents a mid-range tractor within the International Harvester lineup, likely from the late 1960s to early 1970s, building upon previous models and predecessors.
Production Period Estimate:
Likely manufactured between 1968-1975, concurrent with IH's major tractor production phases.
