The International Harvester 684 is a 2WD or 4WD utility tractor from the 84 series. This tractor was manufactured by International Harvester in Doncaster, England from 1977 to 1984. The IH 684 is equipped with a 3.9 L (239.0 cu·in) six-cylinder diesel engine and one of two transmissions: a syncromesh transmission with 8 forward and 4 reverse gears and dry disc clutch or a two-speed power shift transmission with 16 forward and 8 reverse gears.
The International 684 utility tractor used the International Harvester D-239 engine. It is a 3.9 L, 3,916 cm2, (239.0 cu·in) six-cylinder natural aspirated diesel engine with 98.0 mm (3.86 in) of the cylinder bore and 129.0 mm (5.08 in) of the piston stroke. This engine produced 70 PS (51.5 kW; 69.0 HP) at 2,400 rpm of output power.
The IH 684 is equipped with power steering, independent hydraulic wet disc brakes, ROPS canopy or cab (optional) and 75.7 liters (20 US gal.; 16.7 Imp. gal) fuel tank.
International Harvester 684 Specifications
| General Specifications | |
| Model | International Harvester 684 |
| Length | Utility: 3,600 mm (141.7 in) Row-crop: 3,530 mm (139.0 in) 4WD: 3,730 mm (147.2 in) Low-profile: 3,600 mm (141.7 in) |
| Width | Utility: 1,870 mm (73.6 in) Row-crop: 1,900 mm (74.8 in) 4WD: 1,870 mm (73.6 in) Low-profile: 1,990 mm (78.5 in) |
| Height (steering wheel) | Utility : 1,600 mm (63 in) Row-crop: 1,600 mm (63 in) 4WD: 1,600 mm (63 in) Low-profil: 1,430 mm (56.3 in) |
| Wheel base | Utility: 2,230 mm (87.8 in) Row-crop: 2,140 mm (84.3 in) 4WD: 2,160 mm (85.2 in) Low-profil: 2,120 mm (83.7 in) |
| Ground clearance | Utility: 450 mm (17.7 in) Row-crop: 450 mm (17.7 in) 4WD: 450 mm (17.7 in) Low-profil: 270 mm (10.6 in) |
| Weight (shipping) | Utility: 2,595 kg (5,721 lbs) Row-crop: 2,710 kg (5,975 lbs) 4WD: 3,068 kg (6,765 lbs) Low-profil: 2,550 kg (5,620 lbs) |
| Fuel tank capacity | 75.7 liters (20 US gal.; 16.7 Imp. gal) |
| Battery | 12V |
| Cabin type | ROPS canopy or cab (optional) |
| Engine | |
| Engine model | International Harvester D-239 |
| Engine type | Four-stroke, liquid-cooled, inline |
| Cylinders | 6 |
| Fuel type | Diesel |
| Displacement | 3.9 L, 3,916 cm2, (239.0 cu·in) |
| Bore and stroke | 98.0 mm X 129.0 mm (3.86 in X 5.08 in) |
| Horsepower | 70 PS (51.5 kW; 69.0 HP) at 2,400 rpm |
| Starter | Electric |
| Oil capacity: | 8.3 L (8.8 US. qt, 7.3 Imp. qt.) |
| Coolant capacity: | 13.6 L (14.4 US. qt, 12 Imp. qt.) |
| Transmission and chassis | |
| Chassis | 4×2 2WD or 4×4 MFWD 4WD |
| Steering type | Power |
| Brakes | Independent hydraulic wet disc |
| Transmission model | – |
| Transmission type | Syncromesh with dry disc clutch |
| Gears | 8 forward and 4 reverse |
| Speed | Forward: 30.3 kmh (18.8 mph) Reverse: 9.5 (5.9 mph) |
| Transmission oil capacity | 34.1 L (9 US. gal, 7.5 Imp. gal.) |
| Transmission model | Torque Amplifier |
| Transmission type | Two-speed power shift |
| Gears | 16 forward and 8 reverse |
| Speed | Forward: 30.3 kmh (18.8 mph) Reverse: 9.5 (5.9 mph) |
| Transmission oil capacity | 34.1 L (9 US. gal, 7.5 Imp. gal.) |
| Tires | |
| Front tires | Ag: 7.50-16 |
| Rear tires | Ag: 16.9-30 |
| Three-Point Hitch | |
| Category | II |
| Control type | Position and draft control |
| Lift capacity (at ends) | 1,630 kg (3,595 lbs) |
| PTO (Power take-off shaft) | |
| Rear PTO type | Independent with hydraulic wet disc clutch |
| Rear PTO speed | 540 rpm |
| Hydraulic system | |
| Hydraulic type | Open center |
| Hydraulic capacity | 34.1 L (9.0 US. gal, 7.5 Imp. gal.) |
| Valves | 1 or 2 |
| Pump flow | 13.0 gpm (49.2 lpm) 15.4 gpm (58.3 lpm) |

I have an ih 684 and it has a 4 cylinder diesel engine.
I spend many hours in a Ih 484 3-cylinder dieselengine