Tractor · 1981Unverified
International Harvester 3688
International Harvester 3688 — 30 Series · 114 hp. Reference specifications; pending source verification.
Provisional listing — the headline figure is shown; full specifications are auto-generated and pending verification against published sources.
Rated power
114 hp
Max power
74.0 kW
Weight
11300 to 13200 pounds
Hover a source tag to verify
Overview
ManufacturerInternational HarvesterReference
Row-Crop tractorReference
Built in Rock Island, Illinois, USAReference
Total built2,572Reference
Original price was $45,000 in 1981Reference
Two- or four-wheel driveReference
Final drivesbull gearReference
Differential lockrearReference
Power steeringReference
Hydraulic wet disc brakesReference
Cab standard with heat and air-conditioning. Optional burgundy or western finish interiors.Reference
Variants
3688 Hi-Clearhigh-clearance modelReference
Engine
International Harvester 7.1L 6-cyl dieselReference
Drawbar (claimed)74.7 kWReference
Drawbar (tested)74.0 kWReference
International Harvester D436Reference
dieselReference
6-cylinderReference
liquid-cooledReference
Displacement7.1 LReference
Bore/Stroke109 x 127 mmReference
Air cleanerdual dry elmementReference
Compression16:1Reference
Rated RPM2400Reference
Idle RPM900-2400Reference
Starter volts12Reference
Coolant capacity24.6 LReference
Oil capacity13.2 LReference
Power at rated engine speed84.8 kWReference
Max power74.0 kWReference
Transmission
16-speed partial power shiftReference
Typepartial power shiftReference
Gears16 forward and 8 reverseReference
Clutch355.6mm cerametallic discReference
Oil capacity85.2 LReference
Left lever selects gear, right lever selects high, low, or reverse range. Tractor may be shifted on the move without the clutch between gear pairs (1-2, 3-4, etc). Synchronized shifting, using the clutch, between gear pairs (2 to 3, 4 to 5, etc). The transmission is four-gear with the powershift provided by an electric solenoid actuated Torque Amplifier.Reference
PTO & Hydraulics
PTO (claimed)84.3 kWReference
PTO (tested)84.8 kWReference
Hydraulic system85.2 LReference
Typeclosed centerReference
Capacity85.2 LReference
Valves2 to 4Reference
Pump flow68.1 lpmReference
Total flow102.2 lpmReference
Steering flow45.4 lpmReference
Rear TypeIIReference
Controldraft sensingReference
Rear PTOindependentReference
Rear PTO Type540/1000 (1.375)Reference
Engine RPM540@2100Reference
Engine RPM1000@2100Reference
Power at rated PTO speed83.9 kWReference
Capacities
Fuel189.2 LReference
Dimensions
Wheelbase266 cmReference
Weight11300 to 13200 poundsReference
Front tire11L-15Reference
Rear tire18.4-34Reference
Ag front11L-15Reference
Ag rear18.4-34Reference
Length467 cmReference
Width259 cmReference
Height (cab)284 cmReference
Shipping weight5125 kgReference
Operating weight5987 kgReference
Ground clearance33 cmReference
Rear axle82 by 2641 mmReference
Rear axle82 by 2997 mmReference
Front tread152 to 213 cmReference
Rear tread167 to 326 cmReference
3688 Serial Numbers
Location:Serial number plate on the right side of the tractor frame, ahead of the rear axle.Reference
1981501Reference
19821743Reference
19832482Reference
19842695Reference
19853068Reference
FAQ: How to read a serial number table.Reference
Electrical
GroundnegativeReference
Battery volts12Reference
Test results
Diesel 16-speed 2WDMay 26, 1982 - June 7, 1962Link: Nebraska Tractor Test 1440 fileReference
PTO performanceReference
Fuel use28.4 l/hourReference
Fuel use26.9 l/hourReference
Drawbar performanceReference
Max pull5556 kgReference
Speeds
With 18.4-34R1 rear tires.Reference
Values normalized to UK metric units. Every figure is traced to at least one source; verified specs are cross-checked against two or more.