International Harvester 686 Specs ( 1976-1980 )
Overview
The International Harvester 686 is a 2WD farm tractor manufactured between 1976 and 1980 with a total production of 6,000 units. It features a 103-inch wheelbase and was equipped with a 10-speed Torque Amplifier power shift transmission. The model utilized three different 6-cylinder engine types throughout its production, including the C291 gasoline, the D-312 diesel, and the D310 diesel introduced in 1979.
Ideal Applications
Tested Power and Efficiency:
Nebraska Tractor Test 1336 for the 310 diesel variant recorded a maximum PTO output of 66.36 hp at 2000 RPM and a maximum drawbar pull of 8,013 lbs while consuming 4.1 gallons of fuel per hour.
Engine Specifications and Transition:
The tractor was configured with liquid-cooled 6-cylinder engines ranging from a 291 ci gasoline displacement to 310 and 312 ci diesel options, with the German-built D310 replacing the 312 diesel during the 1979 production year.
Chassis and Mechanical Layout:
Constructed with an overall length of 162 inches and a shipping weight of 7,770 lbs, the 686 includes power steering, disc brakes, a two-post fixed ROPS, and an open center hydraulic system with a 12 gpm total flow.
Production
| Description | Original price was $14,700 in 1980 / The International Harvester 686 is nearly identical to the IH 666, it was simply renamed when the 86 series arrived in 1976. One major change did occur in 1979, when the 310 diesel replaced the 312. |
|---|---|
| Manufacturer | International Harvester |
| Total built | 6,000 |
Engine
| Air cleaner | dry |
|---|---|
| Bore/Stroke | 3.875x4.375 inches (98 x 111 mm) / 3.875x4.410 inches (98 x 112 mm) / 3.75x4.39 inches (95 x 112 mm) |
| Coolant capacity | 21 qts (19.9 L) |
| Description | International Harvester D310 / diesel / 6-cylinder / liquid-cooled / German (Nuess) built diesel that replaced the 312 diesel in 1979. / International Harvester D-312 / diesel / 6-cylinder / liquid-cooled / International Harvester C291 / gasoline / 6-cylinder / liquid-cooled |
| Displacement | 310 ci (5.1 L) / 312 ci (5.1 L) / 291 ci (4.8 L) |
| Idle RPM | 900-2000 |
| Oil capacity | 12 qts (11.4 L) |
| Rated RPM | 2000 / 2000 / 2000 |
| Starter volts | 12 |
| Engine type | International Harvester 5.1L 6-cyl diesel / International Harvester 4.8L 6-cyl gasoline |
| Engine type | International Harvester 5.1L 6-cyl diesel / International Harvester 4.8L 6-cyl gasoline |
| Drawbar (tested) | 58.01 hp (43.3 kW) |
| PTO (tested) | 66.36 hp (49.5 kW) |
Transmission
| Gears | 10 forward and 2 reverse |
|---|---|
| Oil capacity | 64 qts (60.6 L) |
| Transmission | Torque Amplifier |
| Transmission type | 10-speed two-speed power shift |
| Type | two-speed power shift |
Mechanical
| Description | Power steering / Disc brakes / Two-post fixed ROPS. |
|---|---|
| Drive type | Two-wheel drive |
Capacity
| Fuel | 31 gal (117.3 L) |
|---|---|
| Hydraulic system | 16 gal (60.6 L) |
Hydraulics
| Capacity | 16 gal (60.6 L) |
|---|---|
| Total flow | 12 gpm (45.4 lpm) |
| Type | open center |
Hitch
| Rear Type | II |
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PTO
| Rear PTO | independent |
|---|---|
| Rear PTO Type | 540 (1.375) |
Dimensions & Tires
| Ballasted weight | 10340 lbs (4690 kg) |
|---|---|
| Diesel Shipping weight | 7770 lbs (3524 kg) |
| Front tread | 58 to 82 inches (147 to 208 cm) |
| Height (exhaust) | 105 inches (266 cm) |
| Length | 162 inches*Overall length with 3-point hitch (411 cm) |
| Rear tread | 56 to 96 inches (142 to 243 cm) |
| Wheelbase | 103 inches (261 cm) |
| Width | 89.4 inches*Minimum width (227 cm) |
| Front tire | 7.50-16 |
| Rear tire | 15.5-38 |
| Weight | 7770 lbs (3524 kg) |
| Wheelbase | 103 inches (261 cm) |
| Ag front | 7.50-16 |
| Ag rear | 15.5-38 |
686 Serial Numbers
| 1976 | 7500 |
|---|---|
| 1977 | 7729 |
| 1978 | 9899 |
| 1979 | 11417 |
| 1980 | 12923 |
| Description | FAQ: How to read a serial number table. |
| Location: | Clutch housing on right side. |
Nebraska Tractor Test 1151
| Description | 312 diesel Torque Amplifier 2WDNovember 3 - 14, 1973Link: Nebraska Tractor Test 1151 file / PTO performance / Drawbar performance / Gear 3-Direct used for power test. / Gear 2-TA used for pull test. |
|---|---|
| Fuel use | 4.7 gal/hour (17.8 l/hour) / 4.6 gal/hour (17.4 l/hour) |
| Max power | 58.01 hp (43.3 kW) |
| Max pull | 8,012 lbs (3634 kg) |
| Power at rated engine speed | 66.29 hp (49.4 kW) |
Nebraska Tractor Test 1152
| Description | Gasoline Torque Amplifier 2WDNovember 5 - December 3, 1973Link: Nebraska Tractor Test 1152 file / PTO performance / Drawbar performance / Gear 3-Direct used for power test. / Gear 2-TA used for pull test. |
|---|---|
| Fuel use | 12.0 gal/hour (45.4 l/hour) / 5.7 gal/hour (21.6 l/hour) |
| Max power | 57.29 hp (42.7 kW) |
| Max pull | 7,981 lbs (3620 kg) |
| Power at rated engine speed | 66.30 hp (49.4 kW) |
Nebraska Tractor Test 1336
| Description | 310 diesel Torque Amplifier 2WDMarch 26 - April 16, 1980Link: Nebraska Tractor Test 1336 file / PTO performance / Drawbar performance / Gear 3-Direct used for power test. / Gear 1-Direct used for pull test. |
|---|---|
| Fuel use | 4.1 gal/hour (15.5 l/hour) / 4.1 gal/hour (15.5 l/hour) |
| Max power | 57.71 hp (43.0 kW) |
| Max pull | 8,013 lbs (3634 kg) |
| Power at rated engine speed | 66.36 hp (49.5 kW) |
References
| Description | 1979 Buyer's Guide published by International Harvester / Agricultural Equipment Reference Catalog published in 1980, by International Harvester |
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Speeds
| Description | With 15.5-38 rear tires. |
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Tractor Tests
| Description | NTTL 1151: 312 diesel Torque Amplifier 2WD / NTTL 1152: gasoline Torque Amplifier 2WD / NTTL 1336: 310 diesel Torque Amplifier 2WD |
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