1986 Jeep Comanche Service Manual

The 1986 Jeep Comanche is a compact pickup truck featuring 2WD and 4WD configurations, available with 2.5L 4-cylinder or 2.8L V6 engines, manual or automatic transmissions, and payload capacities up to 2,205 lbs. This service manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for all major systems including engine, transmission, drivetrain, brakes, suspension, electrical, and body components.

1. Vehicle Specifications 2. Engine Systems 3. Transmission & Drivetrain 4. Brake System 5. Suspension & Steering 6. Electrical System 7. Body & Interior 8. Maintenance Schedule 9. Troubleshooting Guide 10. Safety Precautions 11. Technical Service Bulletins

Vehicle Specifications

Complete technical specifications for 1986 Jeep Comanche models.

SpecificationDescription
Engine Options2.5L I4 (150 CID), 2.8L V6 (173 CID)
Transmission4-speed manual, 5-speed manual, 3-speed automatic
Drivetrain2WD, 4WD (Command-Trac)
Wheelbase113.0 inches (short bed), 119.6 inches (long bed)
Payload Capacity1,100 to 2,205 lbs
Fuel Capacity18.5 gallons
Towing Capacity2,000 to 4,000 lbs (with proper equipment)
Brake SystemFront disc, rear drum with power assist
SuspensionFront: independent, Rear: leaf springs
GVWR4,200 to 5,200 lbs

Engine Systems

Service procedures for 2.5L I4 and 2.8L V6 engines.

  1. Engine removal and installation procedures
  2. Cylinder head service and valve adjustment
  3. Timing chain/belt replacement specifications
  4. Fuel system: carburetor adjustment and fuel pump replacement
  5. Ignition system: distributor timing and spark plug gap settings
  6. Cooling system: radiator flush and thermostat replacement
  7. Exhaust system inspection and repair

WARNING! Always disconnect battery before servicing engine components. Allow engine to cool before opening cooling system.

Transmission & Drivetrain

Manual and automatic transmission service procedures.

  1. Transmission fluid specifications and capacities
  2. Clutch adjustment and replacement (manual transmissions)
  3. Transfer case service for 4WD models
  4. Drive shaft U-joint inspection and replacement
  5. Differential service and gear oil specifications
  6. 4WD system engagement troubleshooting

CAUTION! Use proper jack stands when working under vehicle. Ensure transmission is in park or neutral with parking brake engaged.

Brake System

Suspension & Steering

Front suspension: independent with torsion bars. Rear: leaf springs.

Steering: Recirculating ball type, power steering available.

Alignment Specifications: Toe-in: 1/8" ± 1/16", Camber: 0° ± 1°, Caster: 1.5° ± 1°. Wheel bearing adjustment: Pre-load 17-25 in-lbs while rotating. Torsion bar adjustment: Measure ride height before adjustment. Ball joint inspection: Check for vertical play. Shock absorber replacement: Always replace in pairs.

Electrical System

12-volt negative ground system. Battery: Group 58, 60 amp-hour.

  1. Charging system: Alternator output 56 amps
  2. Starting system: Starter motor specifications and testing
  3. Lighting: Headlight aiming procedure and bulb replacement
  4. Instrument cluster: Gauge testing and sending unit specifications
  5. Wiring diagrams: Color-coded circuit identification
  6. Fuse panel: Location and amperage ratings

Tip: Always disconnect battery before performing electrical work to prevent shorts.

Body & Interior

Body construction: Steel cab with separate bed.

  1. Door adjustment: Hinge and striker plate alignment
  2. Window regulator: Manual crank mechanism service
  3. Seat removal: Bench and bucket seat procedures
  4. Dashboard: Instrument cluster removal and installation
  5. Bed maintenance: Rust prevention and cargo tie-downs
  6. Weatherstripping: Door and window seal replacement

WARNING! Use proper support when removing heavy components like seats or bed. Wear safety glasses when working with glass.

Maintenance Schedule

Recommended service intervals for optimal performance.

IntervalService Items
3,000 milesOil and filter change, tire rotation
6,000 milesLube chassis, check brake system
15,000 milesReplace air filter, check wheel bearings
30,000 milesReplace fuel filter, coolant flush
60,000 milesTiming chain inspection, transmission service

Troubleshooting Guide

Common problems and diagnostic procedures.

SymptomPossible CauseCorrective Action
Engine won't startFuel, spark, or compression issueCheck fuel delivery, spark plugs, compression test
OverheatingCoolant leak, thermostat, water pumpPressure test system, check thermostat operation
Brake pullStuck caliper, contaminated liningsInspect calipers, replace brake pads/shoes
4WD not engagingVacuum system, shift linkageCheck vacuum lines, adjust shift linkage
Electrical issuesGround connections, alternatorTest battery, check grounds, alternator output

Safety Precautions

Essential safety procedures for all service work.

Technical Service Bulletins

Manufacturer-issued updates and corrections.

TSB 86-01: Revised carburetor adjustment procedure for high-altitude operation. TSB 86-07: Updated transmission shift linkage adjustment. TSB 86-15: Brake pedal travel measurement procedure. TSB 86-22: 4WD engagement system vacuum line routing update. For latest TSBs, contact Jeep dealership or service center.

Service Support: Contact Jeep customer service at 1-800-JEEP-USA or visit authorized dealership for technical assistance.

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