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Tractor · 1972Unverified

International Harvester 666

International Harvester 666 — Row-Crop tractor · 75 hp. Reference specifications; pending source verification.

The International Harvester 666 is a tractor with a rated power output of 75 hp, a mid-range figure for its class. It was manufactured from 1972 to 1976. The 666 is equipped with a 6-cylinder diesel liquid-cooled engine, paired with two-wheel drive and hydrostatic transmission. Its operating weight ranges from 6780 to 7420 pounds, making it suitable for operations covering up to 200 acres.

Provisional listing — the headline figure is shown; full specifications are auto-generated and pending verification against published sources.

Rated power
75 hp
Max power
43.3 kW
Weight
6780 to 7420 pounds

Catalogue coverage

Variants represented
2
Richest spec table
117 rows
Recorded power
75 hp
Recorded weight
3075 kg
Transmissions
5-speed
Production years
1972-1976
Verified variants
0

No linked source document is currently displayed; verify critical figures with the manufacturer or dealer.

Hover a source tag to verify

Overview

ManufacturerInternational HarvesterReference
Row-Crop tractorReference
Built in Rock Island, Illinois, USAReference
Total built9,367Reference
Original price$11,875Reference
Torque amplifier was an option. In 1973, the hydrostatic version of the 666 was renamed the 70 Hydro.Reference
Two-wheel driveReference
Power steeringReference
Dry disc brakesReference
Open operator station. Two-post ROPS or canopy optional. Cab available with air-conditioning.Reference

Engine

International Harvester 5.1L 6-cyl dieselReference
International Harvester 4.8L 6-cyl gasolineReference
Gas Fuel tank124.9 LReference
Diesel Fuel tank117.3 LReference
Engine (gross)55.9 kWReference
Drawbar (claimed)42.5 kWReference
Drawbar (claimed)40.3 kWReference
Drawbar (tested)43.3 kWReference
International Harvester D312Reference
dieselReference
6-cylinderReference
liquid-cooledReference
Displacement5.1 LReference
Bore/Stroke98 x 112 mmReference
Power (gross)55.9 kWReference
Fuel systemdirect injectionReference
Air cleanerdual stage dryReference
Compression17:1Reference
Rated RPM2000Reference
Starter volts12Reference
Coolant capacity19.9 LReference
International Harvester C291Reference
gasolineReference
Displacement4.8 LReference
Bore/Stroke95 x 112 mmReference
Compression7.5:1Reference
Power at rated engine speed49.4 kWReference
Max power43.3 kWReference
Power at rated engine speed49.4 kWReference
Max power42.7 kWReference
Power at rated engine speed51.9 kWReference
Max power40.2 kWReference
Power at rated engine speed51.8 kWReference
Max power39.6 kWReference

Transmission

5-speedReference
hydrostaticReference
10-speed two-speed power shiftReference
Transmissionsliding gearReference
Gears5 forward and 1 reverseReference
TypehydrostaticReference
Gearsinfinite forward and reverseReference
TransmissionTorque-AmplifierReference
Typetwo-speed power shiftReference
Gears10 forward and 2 reverseReference
Clutchdry discReference

PTO & Hydraulics

PTO (claimed)48.5 kWReference
PTO (claimed)51.5 kWReference
PTO (tested)51.9 kWReference
Typeopen centerReference
Pump flow45.4 lpmReference
Rear TypeIIReference
TypeIH Fast HitchReference
Rear PTOindependentReference
Rear PTO Type540 (1.375)Reference
Power at rated PTO speed47.8 kWReference
Power at rated PTO speed48.8 kWReference

Dimensions

Wheelbase261 cmReference
Weight6780 to 7420 poundsReference
Front tire7.50-16Reference
Rear tire15.5-38Reference
Ag front7.50-16Reference
Ag rear15.5-38Reference
Length408 cmReference
Width220 cmReference
Height (steering wheel)195 cmReference
Shipping weight3075 kgReference
Shipping weight3365 kgReference
Clearance (front axle)53 cmReference
Clearance (drawbar)35 cmReference
Bar rear axle69 mmReference
Front tread127 to 187 cmReference
Front tread142 to 203 cmReference
Rear tread127 to 243 cmReference

666 Serial Numbers

Location:Clutch housing, right sideReference
19727500Reference
19738200Reference
197411585Reference
197513131Reference
197615739Reference
FAQ: How to read a serial number table.Reference

Electrical

Charging systemalternatorReference
Battery volts12Reference

Test results

NTTL 1151: 312 diesel Torque Amplifier 2WDReference
NTTL 1152: gasoline Torque Amplifier 2WDReference
NTTL 1154: gasoline hydrostatic 2WDReference
NTTL 1155: diesel hydrostatic 2WDReference
312 diesel Torque Amplifier 2WDNovember 3 - 14, 1973Link: Nebraska Tractor Test 1151 fileReference
PTO performanceReference
Fuel use17.8 l/hourReference
Drawbar performanceReference
Fuel use17.4 l/hourReference
Gear 3-Direct used for power test.Reference
Max pull3634 kgReference
Gear 2-TA used for pull test.Reference
Gasoline Torque Amplifier 2WDNovember 5 - December 3, 1973Link: Nebraska Tractor Test 1152 fileReference
Fuel use45.4 l/hourReference
Fuel use21.6 l/hourReference
Max pull3620 kgReference
Gasoline hydrostatic 2WDNovember 14 - December 3, 1973Link: Nebraska Tractor Test 1154 fileReference
Fuel use26.1 l/hourReference
Fuel use22.0 l/hourReference
Fuel use29.1 l/hourReference
Max pull3822 kgReference
Diesel hydrostatic 2WDNovember 14 - December 3, 1973Link: Nebraska Tractor Test 1155 fileReference
Fuel use21.2 l/hourReference
Fuel use20.1 l/hourReference
Max pull3769 kgReference

Values normalized to UK metric units. Every figure is traced to at least one source; verified specs are cross-checked against two or more.

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