International Harvester 3688
Power
125 hp[P] hp
Production
1981-1985
Engine
6-cylinder
Transmission
Partial power shift
Weight
13200 lbs [5987 kg]
Drive
2WD/4WD
From the same series:
Introduction
International Harvester 3688 Row-Crop Tractor
The International Harvester 3688 is a row-crop tractor produced between 1981 and 1985 in Rock Island, Illinois. This machine was designed to deliver consistent performance for heavy-duty agricultural operations, offering a power output of 125 hp.
Engine and Performance
The tractor is powered by a 7.1-liter (436 ci) 6-cylinder liquid-cooled engine. It operates at a rated speed of 2400 RPM with a compression ratio of 16:1. The engine intake is protected by a dual dry element air cleaner, and it features an oil capacity of 13.2 liters.
Transmission and Drivetrain
The 3688 utilizes a partial power shift transmission providing 16 forward and 8 reverse gears. It features a 355.6mm cerametallic disc clutch. The system allows for shifting between gear pairs (1-2, 3-4, etc.) on the move without using the clutch, while synchronized shifting between other gear ranges requires clutch engagement. An electric solenoid-actuated Torque Amplifier facilitates these transitions.
Hydraulics and Hitch
The tractor is equipped with a closed-center hydraulic system providing a total flow of 102.2 lpm (27 gpm), with 68.1 lpm (18 gpm) available at the pump. The hydraulic system supports 2 to 4 valves. The rear hitch is a Category II type featuring draft sensing capabilities for precise implement control.
Operator Environment and Mechanical Features
The machine features a standard climate-controlled cab equipped with both heating and air conditioning. Mechanical control is aided by power steering and hydraulic wet disc brakes. The tractor is available in two- or four-wheel drive configurations and includes a rear differential lock for enhanced traction.
Conclusion
With an operating weight of 5,987 kg and robust structural features such as a 3.25-inch rear axle, the International Harvester 3688 is engineered for demanding row-crop farming tasks. It remains a notable example of early 1980s tractor technology, balancing mechanical power with operator-focused comfort features.
Production Information of International Harvester, 3688
- Original price was $45,000 in 1981
- Row-Crop tractor
- Built in Rock Island, Illinois, USA
| Manufacturer | International Harvester |
|---|---|
| Total built | 2,572 |
Dimension and Tires Information of International Harvester, 3688
| Rear tread | 66 to 128.5 inches [167 to 326 cm] |
|---|---|
| Wheelbase | 105 inches [266 cm] |
| Shipping weight | 11300 lbs [5125 kg] |
| Height (cab) | 112 inches [284 cm] |
| Length | 184 inches [467 cm] |
| Rear axle | 3.25 by 104 inches [82 by 2641 mm] |
| Operating weight | 13200 lbs [5987 kg] |
| Width | 102 inches [259 cm] |
| Front tread | 60 to 84 inches [152 to 213 cm] |
| Rear axle | 3.25 by 118 inches [82 by 2997 mm] |
| Ground clearance | 13 inches [33 cm] |
Width at minimum tread.
| Ag front | 11L-15 |
|---|---|
| Ag rear | 18.4-34 |
Engine Specifications of International Harvester, 3688
- Liquid-cooled
- 6-cylinder
| Starter volts | 12 |
|---|---|
| Displacement | 436 ci [7.1 L] |
| Oil capacity | 14 qts [13.2 L] |
| Compression | 16:1 |
| Bore/Stroke | 4.30x5.00 inches [109 x 127 mm] |
| Coolant capacity | 26 qts [24.6 L] |
| Idle RPM | 900-2400 |
| Rated RPM | 2400 |
| Air cleaner | Dual dry elmement |
Transmission Information of International Harvester, 3688
Transmission variants 1
- Left lever selects gear, right lever selects high, low, or reverse range. Tractor may be shifted on the move without the clutch between gear pairs (1-2, 3-4, etc). Synchronized shifting, using the clutch, between gear pairs (2 to 3, 4 to 5, etc). The transmission is four-gear with the powershift provided by an electric solenoid actuated Torque Amplifier.
| Type | Partial power shift |
|---|---|
| Oil capacity | 90 qts [85.2 L] |
| Gears | 16 forward and 8 reverse |
| Clutch | 355.6mm cerametallic disc |
Mechanical Specs of International Harvester, 3688
- Two- or four-wheel drive
- Hydraulic wet disc brakes
- Power steering
- Cab standard with heat and air-conditioning. Optional burgundy or western finish interiors.
| Final drives | Bull gear |
|---|---|
| Differential lock | Rear |
Power Information of International Harvester, 3688
| Rear PTO | Independent |
|---|---|
| Rear PTO(optional) | 1000@2100 |
| Rear PTO Type | 540/1000 (1.375) |
| Engine RPM | 540@2100 |
Hydraulics Specifications of International Harvester, 3688
| Type | Closed center |
|---|---|
| Total flow | 27 gpm [102.2 lpm] |
| Pump flow | 18 gpm [68.1 lpm] |
| Capacity | 22.5 gal [85.2 L] |
| Steering flow | 12 gpm [45.4 lpm] |
| Valves | 2 to 4 |
Three-Point Hitch of International Harvester, 3688
| Rear Type | II |
|---|---|
| Control | Draft sensing |
Electrical System of International Harvester, 3688
| Ground | Negative |
|---|---|
| Battery volts | 12 |
Where it sits
With 125 hp[P] HP, the International Harvester 3688 sits just above 3488 (124 HP) in International Harvester's range. Its power puts it in the 78th percentile of 1980s models in our database (2052 machines).
Frequently asked questions
How much horsepower does the International Harvester 3688 have?
The International Harvester 3688 delivers 125 hp[P] HP.
What years was the International Harvester 3688 produced?
The International Harvester 3688 was produced in 1981-1985.
What engine does the International Harvester 3688 have?
The International Harvester 3688 is powered by a 6-cylinder engine.
What transmission does the International Harvester 3688 use?
The International Harvester 3688 uses a Partial power shift transmission.
How much does the International Harvester 3688 weigh?
The International Harvester 3688 weighs 13200 lbs [5987 kg].
Is the International Harvester 3688 4WD?
The International Harvester 3688 is available in 2WD/4WD.