1987 GMC R1500 Pickup Repair Manual

The 1987 GMC R1500 Pickup is a full-size light-duty truck featuring rear-wheel drive, V6 or V8 gasoline engines, 4-speed automatic or 5-speed manual transmission, independent front suspension with torsion bars, and rear leaf spring suspension. This comprehensive repair manual covers maintenance, troubleshooting, and repair procedures for engine, transmission, brakes, steering, suspension, electrical systems, and body components. Below are key sections for specifications, maintenance schedules, repair procedures, and troubleshooting.

1. Vehicle Specifications 2. Maintenance Schedule 3. Engine Repair 4. Transmission Service 5. Brake System 6. Steering & Suspension 7. Electrical System 8. Body & Interior 9. Troubleshooting Guide 10. Technical Service Bulletins

Vehicle Specifications

Key technical data for the 1987 GMC R1500 Pickup including engine options, dimensions, capacities, and performance specifications.

Specification	Details
Engine Options	4.3L V6, 5.0L V8, 5.7L V8
Transmission	4-speed automatic, 5-speed manual
Wheelbase	117.5 inches (standard bed)
Payload Capacity	1,500 lbs
Fuel Capacity	25 gallons
Oil Capacity	5 quarts (with filter)
Curb Weight	3,800-4,200 lbs
Brake System	Front disc, rear drum
Front Suspension	Independent with torsion bars
Rear Suspension	Leaf springs

Maintenance Schedule

Recommended maintenance intervals for optimal performance and longevity.

Oil and filter change: Every 3,000 miles or 3 months
Air filter replacement: Every 15,000 miles
Spark plugs: Every 30,000 miles
Coolant flush: Every 30,000 miles or 2 years
Transmission fluid: Every 30,000 miles
Brake fluid: Every 30,000 miles or 2 years
Timing belt: Every 60,000 miles (if equipped)

WARNING! Always use jack stands when working under vehicle. Disconnect battery before electrical work.

Engine Repair

Procedures for engine maintenance, diagnosis, and repair.

Compression testing: Remove spark plugs, test each cylinder
Valve adjustment: Set clearance to 0.015-0.025 inches (cold)
Timing chain/belt replacement: Align timing marks during installation
Carburetor adjustment: Set idle mixture and speed according to specifications
Fuel system: Replace fuel filter every 15,000 miles
Cooling system: Check for leaks, replace thermostat if overheating

CAUTION! Allow engine to cool before opening cooling system. Use proper safety equipment.

Transmission Service

Automatic Transmission: Check fluid level with engine running, transmission in Park
Manual Transmission: Use GL-4 gear oil, check for leaks at seals
Fluid Specifications: Dexron II for automatic, 80W-90 for manual
Shift Linkage: Adjust for proper gear engagement
Clutch Replacement: Inspect flywheel surface, replace pilot bearing
Transmission Removal: Support engine, remove crossmember, lower carefully

Brake System

Brake maintenance and repair procedures including disc brakes, drum brakes, and hydraulic system.

Front Disc Brakes: Replace pads when worn to 1/8 inch, resurface rotors if scored. Rear Drum Brakes: Adjust shoes periodically, replace if lining worn thin. Master Cylinder: Bench bleed before installation. Bleeding Procedure: Start with wheel farthest from master cylinder, use fresh DOT 3 fluid.

Steering & Suspension

Steering gear adjustment, ball joint replacement, and suspension component service.

Check ball joints: Lift front end, check for play in wheels
Inspect tie rod ends: Replace if excessive play detected
Torsion bar adjustment: Use special tool to adjust ride height
Shock absorber replacement: Always replace in pairs
Wheel alignment: Set toe-in to 1/8 inch, caster 2-3 degrees positive

Tip: Mark alignment settings before disassembly for easier reassembly.

Electrical System

Diagnosis and repair of charging, starting, and lighting systems.

Battery testing: Load test to determine condition
Alternator output: Should be 13.5-14.5 volts at 2,000 RPM
Starter draw: Maximum 180 amps for V8 engines
Wiring diagrams: Use factory diagrams for circuit tracing
Fuse panel: Located under dashboard on driver's side
Ground connections: Clean and tighten for proper circuit operation

WARNING! Disconnect battery before electrical repairs to prevent shorts and injury.

Body & Interior

Body panel alignment, door adjustment, and interior component service.

Troubleshooting Guide

Common problems and their solutions for quick diagnosis.

Symptom	Possible Cause	Corrective Action
Engine cranks but won't start	Fuel pump, ignition module	Check fuel pressure, test spark, verify ignition timing
Transmission slips	Low fluid, worn bands	Check fluid level and condition, adjust bands if applicable
Brake pedal goes to floor	Master cylinder, leaks	Inspect for fluid leaks, rebuild or replace master cylinder
Steering wander	Alignment, worn components	Check alignment, inspect tie rods and ball joints
Electrical drain	Alternator, short circuits	Perform parasitic draw test, isolate circuit causing drain

Reset: Disconnect battery for 30 minutes to reset computer memory.

Service: Refer to factory service manual for detailed specifications

Technical Service Bulletins

Factory-issued updates and corrections for known issues.

TSB 87-45: Carburetor idle mixture adjustment procedure. TSB 87-52: Transmission shift cable lubrication. TSB 87-68: Brake pedal return spring replacement. TSB 87-79: Instrument cluster ground connection. Contact GMC dealership for complete TSB listings and updates.