The 1986 GMC K2500 is a three-quarter ton pickup truck featuring 4-wheel drive capability, powerful V8 engine options, heavy-duty suspension, and rugged construction designed for both work and recreational use. This manual covers operation, maintenance, specifications, and troubleshooting for your vehicle. Below are key sections for vehicle features, operation procedures, maintenance schedules, specifications, and troubleshooting guidance.
Key components: Heavy-duty chassis, 4-wheel drive system, V8 engine, manual or automatic transmission, dual fuel tanks, and rugged suspension.
| Feature | Description |
|---|---|
| Engine Options | 5.0L V8, 5.7L V8, or 7.4L V8 gasoline engines |
| Transmission | 4-speed manual or 3-speed automatic |
| Drivetrain | Part-time 4-wheel drive with 2-speed transfer case |
| Payload Capacity | Up to 2,500 lbs depending on configuration |
| Towing Capacity | Up to 8,000 lbs with proper equipment |
| Fuel System | Dual fuel tanks with selector switch |
| Suspension | Heavy-duty leaf springs front and rear |
| Brakes | Power front disc and rear drum brakes |
| Bed Length | 6.5 ft or 8 ft styleside or fleetside |
| GVWR | 8,600 lbs maximum |
Familiarize yourself with the gauges, warning lights, and controls.
WARNING! Never ignore warning lights; stop vehicle immediately if red warning lights illuminate.
Proper starting and driving procedures for optimal performance.
CAUTION! Allow engine to warm up in cold weather before driving.
Regular maintenance ensures longevity and reliability.
Every 3,000 miles: Oil and filter change, check fluid levels
Every 6,000 miles: Rotate tires, inspect brakes, check steering
Every 12,000 miles: Replace air filter, check spark plugs
Every 30,000 miles: Change automatic transmission fluid, check 4WD system
Every 50,000 miles: Replace coolant, inspect timing chain
Engine Oil: 5 quarts with filter
Tip: Use only recommended fluids specified in this manual.
Proper loading and towing procedures for safety.
WARNING! Never exceed GVWR or towing capacity ratings.
Part-time 4-wheel drive system operation.
2WD: Normal driving on dry pavement
4HI: Slippery roads, snow, gravel
4LO: Extreme conditions, heavy towing, steep grades
Standard safety equipment and precautions.
CAUTION! Always wear seat belts. Keep children in proper restraints. Never leave children unattended in vehicle.
Basic warranty: 12 months/12,000 miles. Powertrain warranty: 36 months/36,000 miles. Rust-through warranty: 36 months/unlimited miles. See your GMC dealer for complete warranty details and limitations.
| Symptom | Possible Cause | Corrective Action |
|---|---|---|
| Engine won't start | Battery, fuel, ignition | Check battery connections, fuel level, spark plugs |
| Rough idle | Spark plugs, carburetor | Replace spark plugs, adjust carburetor mixture |
| 4WD won't engage | Linkage, vacuum | Check shift linkage, vacuum lines to front axle |
| Overheating | Coolant, thermostat | Check coolant level, replace thermostat if stuck |
| Brake pulsation | Warped rotors | Have rotors resurfaced or replaced |
Service: Contact your local GMC dealer for professional service.