| Manufacturer | Farmall |
| Price | 11,875(USD) |
| Model | 666 |
| Equipment Type | - |
| Factory |
NEBRASKA TRACTOR TEST 1151 2
| Description | 312 diesel Torque Amplifier 2WD November 3 - 14, 1973 Link: Nebraska Tractor Test 1151 file PTO performance Drawbar performance Gear 3-Direct used for power test Gear 2-TA used for pull test |
| Power at rated engine speed | 66.29hp / 49.4kW |
| Fuel use | 4.6gal/hour / 17.4l/hour |
| Max power | 58.01hp / 43.3kW |
| Max pull | 8,012lbs / 3634kg |
NEBRASKA TRACTOR TEST 1152 2
| Description | Gasoline Torque Amplifier 2WD November 5 - December 3, 1973 Link: Nebraska Tractor Test 1152 file PTO performance Drawbar performance Gear 3-Direct used for power test Gear 2-TA used for pull test |
| Power at rated engine speed | 66.30hp / 49.4kW |
| Fuel use | 5.7gal/hour / 21.6l/hour |
| Max power | 57.29hp / 42.7kW |
| Max pull | 7,981lbs / 3620kg |
NEBRASKA TRACTOR TEST 1154 2
| Description | Gasoline hydrostatic 2WD November 14 - December 3, 1973 Link: Nebraska Tractor Test 1154 file PTO performance Drawbar performance |
| Power at rated engine speed | 69.61hp / 51.9kW |
| Fuel use | 7.7gal/hour / 29.1l/hour |
| Power at rated PTO speed | 64.10hp / 47.8kW |
| Max power | 53.86hp / 40.2kW |
| Max pull | 8,427lbs / 3822kg |
NEBRASKA TRACTOR TEST 1155 2
| Description | Diesel hydrostatic 2WD November 14 - December 3, 1973 Link: Nebraska Tractor Test 1155 file PTO performance Drawbar performance |
| Power at rated engine speed | 69.51hp / 51.8kW |
| Fuel use | 5.6gal/hour / 21.2l/hour |
| Power at rated PTO speed | 65.41hp / 48.8kW |
| Max power | 53.10hp / 39.6kW |
| Max pull | 8,310lbs / 3769kg |
FARMALL 666 POWER
| Drawbar (tested) | 58.01hp / 43.3kW |
| PTO (tested) | 69.61hp / 51.9kW |
ENGINES OVERVIEW
The Farmall 666 tractor is powered by either a 5.1L 6-cylinder diesel engine or a 4.8L 6-cylinder gasoline engine, offering flexibility in fuel choice. The diesel variant provides superior torque and fuel efficiency, making it ideal for heavy-duty tasks, while the gasoline engine may offer easier starting and lower initial costs. However, the diesel engine's higher maintenance demands and initial investment can be a challenge, particularly for small-scale farmers.
| Description | International Harvester 5.1L 6-cyl diesel International Harvester 4.8L 6-cyl gasoline |
ENGINE DETAIL 1
The Farmall 666 features a robust International Harvester D312 diesel engine, providing a substantial displacement of 5.1L with a high compression ratio of 17:1, optimizing efficiency and torque output. Its dual-stage dry air cleaner enhances engine longevity by ensuring cleaner air intake, crucial for maintaining performance under heavy load conditions. With a rated RPM of 2000, this tractor is suited for tasks requiring steady power delivery, making it ideal for mid-sized farming operations but may face challenges with excessively heavy implements due to its power profile.
| Description | International Harvester D312 diesel 6-cylinder liquid-cooled |
| Displacement | 312ci / 5.1L |
| Bore/Stroke | 3.875x4.410inches / 98x 112mm |
| Air cleaner | dual stage dry |
| Compression | 17:1 |
| Rated RPM | 2000 |
| Starter volts | 12 |
ENGINE DETAIL 2
The Farmall 666 features the International Harvester C291 engine, offering a 291ci displacement and 6-cylinder configuration, ideal for moderate power demands on medium-sized farms. With a compression ratio of 7.5:1 and rated RPM of 2000, this tractor provides a good balance between torque and fuel efficiency, although the lower RPM may limit peak power for heavy-duty applications. Its dual-stage dry air cleaner aids in improving engine longevity by preventing particulate contamination, making it suitable for diverse farming conditions.
| Description | International Harvester C291 gasoline 6-cylinder liquid-cooled |
| Displacement | 291ci / 4.8L |
| Bore/Stroke | 3.75x4.39inches / 95x 112mm |
| Air cleaner | dual stage dry |
| Compression | 7.5:1 |
| Rated RPM | 2000 |
| Starter volts | 12 |
FARMALL 666 ENGINES
The Farmall 666 is equipped with either a 5.1L diesel or a 4.8L gasoline engine, offering farmers options for fuel efficiency or power output. The diesel engine typically provides greater torque and fuel economy, making it advantageous for heavy-duty applications, while the gasoline variant may offer easier maintenance and lower initial costs. It's important to assess operational needs, as the diesel engine excels in longevity and load capacity, whereas gasoline might be preferable for lighter, more versatile tasks.
| Description | International Harvester 5.1L 6-cyl diesel International Harvester 4.8L 6-cyl gasoline |
TRANSMISSIONS OVERVIEW
The Farmall 666 tractor features a 5-speed hydrostatic system paired with a 10-speed partial power shift, providing smooth and efficient control over varying load conditions. The hydrostatic drive allows for excellent maneuverability, particularly in tight spaces, while the partial power shift enhances productivity during field operations by reducing the need for frequent clutch engagement. However, the complexity of repair and maintenance for these systems may present challenges for operators unfamiliar with advanced transmission technology.
| Description | 5-speed hydrostatic 10-speed partial power shift |
TRANSMISSION 1
The Farmall 666's sliding gear transmission offers simplicity and reliability, but can lead to increased wear if not properly maintained. With 5 forward and 1 reverse gear, it provides adequate versatility for various farming tasks, although the limited gear range may restrict its performance in certain field conditions. This transmission is ideal for light to moderate agricultural activities but may pose challenges in more demanding applications, where greater gear options are beneficial.
| Transmission | sliding gear |
| Gears | 5 forward and 1 reverse |
TRANSMISSION 2
The Farmall 666 tractor features a hydrostatic transmission with infinite forward and reverse gearing, providing seamless speed adjustments for precise control in various farming tasks. This system minimizes operator fatigue and enhances maneuverability in tight spaces, making it ideal for applications such as orcharding or landscaping. However, hydrostatic systems may have lower efficiency in power transmission compared to traditional gear transmissions, which could impact performance in heavy-duty applications.
| Type | hydrostatic |
| Gears | infinite forward and reverse |
TRANSMISSION 3
The Farmall 666 features a partial power shift transmission with a Torque-Amplifier, allowing for smoother gear transitions and improved torque management under load. With 10 forward and 2 reverse gears, it offers versatility for various farming tasks, though the dry disc clutch may necessitate more frequent maintenance compared to hydraulic alternatives. Optimal for mid-range field applications, the machine provides a balance of power and control, however, operators should be cautious of potential challenges in high-slip scenarios.
| Transmission | Torque-Amplifier |
| Type | partial power shift |
| Gears | 10 forward and 2 reverse |
| Clutch | dry disc |
MECHANICAL
The Farmall 666 features a 4x2 2WD chassis, ideal for lighter agricultural tasks, but may struggle with traction in muddy conditions. Its hydrostatic power steering enhances maneuverability, while the dry disc brakes provide reliable stopping power but require regular maintenance to avoid fading. The optional two-post ROPS or canopy offers safety, although the open operator station may expose the driver to the elements during prolonged use.
| Chassis | 4x2 2WD |
| Steering | hydrostatic power |
| Brakes | dry disc |
| Cab | Open operator station Two-post ROPS or canpoy optional |
| Transmissions | 5-speed hydrostatic 10-speed partial power shift |
TRACTOR HITCH
| Rear Type | II |
| Type | IH Fast Hitch |
POWER TAKE-OFF (PTO)
| Rear PTO | independent |
| Rear RPM | 540 |
FARMALL 666 TIRES
The Farmall 666 tractor features 7.50-16 Ag front tires and 15.5-38 Ag rear tires, providing a balanced mix of flotation and traction for various farming applications. The larger rear tires enhance stability and power transfer during tillage or heavy hauling, while the front tires ensure agility and maneuverability in tight spaces. However, the tire selection may limit performance in muddy conditions, potentially requiring additional tire options for enhanced traction.
| Ag front | 7.50-16 |
| Ag rear | 15.5-38 |
DIMENSIONS
| Wheelbase | 103inches / 261cm |
| Weight | 7053lbs / 3199kg |
DIMENSIONS & TIRES
The Farmall 666 features a wheelbase of 103 inches, providing stability for field operations. Its weight of 7,053 lbs contributes to traction but could present challenges in compacted or wet soils. The front and rear tire sizes are optimal for a balance of load capacity and maneuverability, making it suitable for diverse agricultural tasks, though tire selection may impact performance in certain terrains.
| Wheelbase | 103inches / 261cm |
| Weight | 7053lbs / 3199kg |
| Front tire | 7.50-16 |
| Rear tire | 15.5-38 |
666 SERIAL NUMBERS
| Location | Clutch housing, right side |
| 1972 | 7500 |
| 1973 | 8200 |
| 1974 | 11585 |
| 1975 | 13131 |
| 1976 | 15739 |