Farmall 666
The Farmall 666 is a tractor produced by Farmall. It is equipped with a 291 ci 4.8 L engine. The rated power output is 75 hp 55.9 kW. Transmission: Torque-Amplifier. Operating weight: 6780 to 7420 pounds.
Engine Power
75 hp
55.9 kW
Fuel & Capacities
Gasoline
Transmission
Torque-Amplifier
Operating Weight
6780 to 7420 pounds
Farmall 666 Serial Number & Year Decoder
Find the exact manufacture year of your tractor by checking your chassis serial number below.
Where to Find the Serial NumberThe serial number plate is commonly located on the front frame, tractor transmission housing (right side), or instrument panel badge.
Overview
![]() | 1972 - 1976
Row-Crop tractor |
|---|---|
1972 - 1976 | |
Row-Crop tractor | |
Note: the Farmall model 666 is the same as the International Harvester 666. The following data is from the 666 listing. |
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Production | |
|---|---|
Manufacturer | Farmall (a part of International Harvester) |
Row-Crop tractor | |
Built in Rock Island, Illinois, USA | |
Total built | 9,367 |
Original price | $11,875 |
Farmall 666 Power | |
|---|---|
Engine (gross) | 75 hp
55.9 kW |
Drawbar (claimed) | 57 hp (gear)
42.5 kW |
54 hp (hydro)
40.3 kW | |
PTO (claimed) | 65 hp (gear)
48.5 kW |
69 hp (hydro)
51.5 kW | |
Drawbar (tested) | 58.01 hp
43.3 kW |
PTO (tested) | 69.61 hp
51.9 kW |
Performance test details ... | |
Mechanical | |
|---|---|
Two-wheel drive | |
Power steering | |
Dry disc brakes | |
Open operator station. Two-post ROPS or canopy optional. Cab available with air-conditioning. |
Hydraulics | |
|---|---|
Type | open center |
Pump flow | 12 gpm
45.4 lpm |
Tractor hitch | |
|---|---|
Rear Type | II |
Type | IH Fast Hitch |
Power Take-off (PTO) | |
|---|---|
Rear PTO | independent |
Rear PTO Type | 540 (1.375) |
Dimensions & Tires | |
|---|---|
Wheelbase | 103 inches
261 cm |
Weight | 6780 to 7420 pounds |
Front tire | 7.50-16 |
Rear tire | 15.5-38 |
Full dimensions and tires ... | |
Electrical | |
|---|---|
Charging system | alternator |
Battery volts | 12 |
References | |
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![]() | |
Farm Equipment Reference Catalog published in 1972, by International Harvester |
Engine
Note: the Farmall model 666 is the same as the International Harvester 666. The following data is from the 666 listing. |
|---|
Engine options | |
|---|---|
International Harvester 5.1L 6-cyl diesel | |
International Harvester 4.8L 6-cyl gasoline |
Engine Detail — 312 ci / 5.1 L Diesel
Manufacturer | International Harvester D312 |
Fuel Type | Diesel |
Configuration | 6-cylinder, liquid-cooled |
Displacement | 312 ci
5.1 L |
Bore/Stroke | 3.875x4.410 inches
98 x 112 mm |
Power (gross) | 75 hp
55.9 kW |
Fuel system | direct injection |
Air cleaner | dual stage dry |
Compression | 17:1 |
Rated RPM | 2000 |
Starter volts | 12 |
Coolant capacity | 21 qts
19.9 L |
Engine Detail — 291 ci / 4.8 L Gasoline
Manufacturer | International Harvester C291 |
Fuel Type | Gasoline |
Configuration | 6-cylinder, liquid-cooled |
Displacement | 291 ci
4.8 L |
Bore/Stroke | 3.75x4.39 inches
95 x 112 mm |
Power (gross) | 75 hp
55.9 kW |
Air cleaner | dual stage dry |
Compression | 7.5:1 |
Rated RPM | 2000 |
Starter volts | 12 |
Coolant capacity | 21 qts
19.9 L |
Transmission
Note: the Farmall model 666 is the same as the International Harvester 666. The following data is from the 666 listing. |
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Transmission options | |
|---|---|
5-speed | |
hydrostatic | |
10-speed two-speed power shift |
Transmission — sliding gear
Transmission | sliding gear |
Gears | 5 forward and 1 reverse |
Transmission — infinite forward and reverse hydrostatic
Type | hydrostatic |
Gears | infinite forward and reverse |
![]() | |
Transmission — Torque-Amplifier
Transmission | Torque-Amplifier |
Type | two-speed power shift |
Gears | 10 forward and 2 reverse |
Clutch | dry disc |
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Dimensions
Note: the Farmall model 666 is the same as the International Harvester 666. The following data is from the 666 listing. |
|---|
Farmall 666 Tires | |
|---|---|
Ag front | 7.50-16 |
Ag rear | 15.5-38 |
Dimensions | |
|---|---|
Wheelbase | 103 inches
261 cm |
Length | 161 inches
408 cm |
Width | 87 inches
220 cm |
Height (steering wheel) | 77 inches
195 cm |
Shipping weight | 6780 lbs (gas gear)
3075 kg |
7420 lbs (diesel hydro)
3365 kg | |
Clearance (front axle) | 21 inches
53 cm |
Clearance (drawbar) | 14 inches
35 cm |
Front tread | 50 to 74 inches
127 to 187 cm |
Front tread | 56 to 80 inches
142 to 203 cm |
Rear tread | 50 to 96 inches
127 to 243 cm |
Tests
Note: the Farmall model 666 is the same as the International Harvester 666. The following data is from the 666 listing. |
|---|
Tractor Tests | |
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NTTL 1151: 312 diesel Torque Amplifier 2WD | |
NTTL 1152: gasoline Torque Amplifier 2WD | |
NTTL 1154: gasoline hydrostatic 2WD | |
NTTL 1155: diesel hydrostatic 2WD |
Nebraska Tractor Test 1151 | |
|---|---|
312 diesel Torque Amplifier 2WD
November 3 - 14, 1973
Link: Nebraska Tractor Test 1151 file | |
PTO performance | |
Power at rated engine speed | 66.29 hp
49.4 kW |
Fuel use | 4.7 gal/hour
17.8 l/hour |
Drawbar performance | |
Max power | 58.01 hp
43.3 kW |
Fuel use | 4.6 gal/hour
17.4 l/hour |
Gear 3-Direct used for power test. | |
Max pull | 8,012 lbs
3634 kg |
Gear 2-TA used for pull test. | |
Nebraska Tractor Test 1152 | |
|---|---|
Gasoline Torque Amplifier 2WD
November 5 - December 3, 1973
Link: Nebraska Tractor Test 1152 file | |
PTO performance | |
Power at rated engine speed | 66.30 hp
49.4 kW |
Fuel use | 12.0 gal/hour
45.4 l/hour |
Drawbar performance | |
Max power | 57.29 hp
42.7 kW |
Fuel use | 5.7 gal/hour
21.6 l/hour |
Gear 3-Direct used for power test. | |
Max pull | 7,981 lbs
3620 kg |
Gear 2-TA used for pull test. | |
Nebraska Tractor Test 1154 | |
|---|---|
Gasoline hydrostatic 2WD
November 14 - December 3, 1973
Link: Nebraska Tractor Test 1154 file | |
PTO performance | |
Power at rated engine speed | 69.61 hp
51.9 kW |
Fuel use | 6.9 gal/hour
26.1 l/hour |
Power at rated PTO speed | 64.10 hp
47.8 kW |
Fuel use | 5.8 gal/hour
22.0 l/hour |
Drawbar performance | |
Max power | 53.86 hp
40.2 kW |
Fuel use | 7.7 gal/hour
29.1 l/hour |
Max pull | 8,427 lbs
3822 kg |
Nebraska Tractor Test 1155 | |
|---|---|
Diesel hydrostatic 2WD
November 14 - December 3, 1973
Link: Nebraska Tractor Test 1155 file | |
PTO performance | |
Power at rated engine speed | 69.51 hp
51.8 kW |
Fuel use | 5.6 gal/hour
21.2 l/hour |
Power at rated PTO speed | 65.41 hp
48.8 kW |
Fuel use | 5.3 gal/hour
20.1 l/hour |
Drawbar performance | |
Max power | 53.10 hp
39.6 kW |
Fuel use | 5.6 gal/hour
21.2 l/hour |
Max pull | 8,310 lbs
3769 kg |
Photos
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