🏷️ Basic Information

Make:

Jeep

Model:

Comanche

Body Style:

Pickup Truck

Market Segment:

Compact/Mid-size Pickup Truck

Product Type:

Service Repair Manual

Chassis Code:

XJ (shared with Cherokee)

👋 Introduction

Positioning:

The Jeep Comanche (MJ) was a compact pickup truck produced by Jeep from 1986 to 1992, sharing its unibody platform with the popular Cherokee (XJ). It aimed to compete in the growing compact pickup market, offering Jeep's renowned off-road capability in a utilitarian package.

Competitors:

Primary competitors included the Ford Ranger, Chevrolet S-10, GMC S-15 Sonoma, and Nissan Hardbody. The Comanche differentiated itself with its unibody construction, robust drivetrain options, and strong off-road heritage.

Unique Selling Points:

Unibody construction (lighter and stiffer than body-on-frame), available 4.0L inline-six engine, legendary Jeep 4x4 capability, relatively compact size for maneuverability.

Value For Owners:

This comprehensive service manual is essential for owners looking to maintain, diagnose, and repair their Jeep Comanche. It provides the same detailed information found in dealership service bays, empowering DIY enthusiasts and professional mechanics alike.

📋 Manual Details

Model Years Covered:

1986, 1987, 1988, 1989, 1990, 1991, 1992

Geographic Coverage:

Primarily North American specifications, with global applicability for core mechanicals.

Estimated Page Count:

Over 1500 pages (typical for comprehensive service manuals of this era)

Type:

Factory Service Manual (FSM) / Workshop Manual

Content Focus:

Repair, Maintenance, Diagnostics, Specifications

Language:

English

Format:

Digital Download (PDF)

📖 Manual Coverage

Engine Mechanical:

Diagnosis, repair, overhaul, specifications for 2.5L I4, 4.0L I6, and 4.2L I6 engines.

Engine Performance:

Fuel injection systems (Renix EFI), ignition systems, emission controls, cooling system.

Transmission:

Manual transmissions (AX-4, AX-5, NV2500), Automatic transmissions (AW-4, Aisin-Warner).

Drivetrain:

Transfer case (NP231, NP242), Dana 30 front axle, Dana 35 rear axle, NP242 Command-Trac, 4WD system.

Suspension:

Front and rear suspension systems, leaf springs, coil springs, shock absorbers, sway bars.

Steering:

Power steering system, steering column, steering linkage, steering gear.

Brakes:

Front disc brakes, rear drum brakes, ABS (if equipped), hydraulic system, parking brake.

Electrical:

Battery, starting system, charging system, lighting system, wiring diagrams for all circuits.

Body And Interior:

Body panels, doors, windows, seats, HVAC system, interior trim, body repair procedures.

HVAC:

Air conditioning system, heater core, blower motor, controls, refrigerant.

Exhaust System:

Exhaust manifold, catalytic converter, muffler, pipes.

Fuel System:

Fuel tank, fuel pump, fuel lines, fuel injectors, fuel pressure regulator.

Maintenance:

Scheduled maintenance, oil changes, filter replacements, fluid checks, tune-ups.

Troubleshooting:

Diagnostic flowcharts, symptom analysis, common problems and solutions.

Repair:

Step-by-step repair instructions for all major components and systems.

Overhaul:

Complete engine and transmission rebuild procedures.

Diagnostics:

On-board diagnostics (OBD-I) interpretation, sensor testing, actuator testing.

Wiring Diagrams:

Detailed electrical schematics for all vehicle circuits.

Depth:

Comprehensive, covering everything from basic fluid checks to full engine and transmission overhauls.

Diagnostics Level:

Advanced diagnostic procedures including component testing and troubleshooting.

Illustration Quality:

Illustrated with clear, step-by-step diagrams and photos (as per description).

📊 Manual Specifications

Format Type:

PDF (Portable Document Format)

Searchability:

Likely text-searchable if OCR'd properly, enhancing ease of use.

Print Readability:

Designed for clear printing, allowing users to take it into the garage.

Original Binding:

Stapled or perfect bound (factory original); Digital format offers no physical binding.

Original Paper:

Typically printed on durable, shop-resistant paper (factory original).

⚙️ Engine Specifications

Engine 1 Variant:

2.5L AMC I4 (150 cu in)

Engine 1 Fuel System:

Renix Multi-Port Fuel Injection (MPI)

Engine 1 Power Hp:

Approx. 115 hp @ 4600 RPM

Engine 1 Torque Lb Ft:

Approx. 135 lb-ft @ 2400 RPM

Engine 2 Variant:

4.0L AMC I6 (242 cu in) 'High Output'

Engine 2 Fuel System:

Renix Multi-Port Fuel Injection (MPI)

Engine 2 Power Hp:

Approx. 173 hp @ 4700 RPM (later models 190+ hp)

Engine 2 Torque Lb Ft:

Approx. 220 lb-ft @ 3200 RPM (later models 225+ lb-ft)

Engine 3 Variant:

4.2L AMC I6 (258 cu in)

Engine 3 Fuel System:

Fuel Injection (early models) or Carbureted (late models)

Engine 3 Power Hp:

Approx. 116 hp @ 3200 RPM

Engine 3 Torque Lb Ft:

Approx. 210 lb-ft @ 2000 RPM

Injection Type:

Renix (Renault Electronics/Engine Management) EFI system, later models adopted Chrysler EFI.

Fuel Type:

Unleaded gasoline

🔧 Transmission

Transmission 1:

AX-4 4-speed manual (early models, 2.5L)

Transmission 2:

AX-5 5-speed manual (common, especially with 4.0L)

Transmission 3:

NV2500 5-speed manual (heavy-duty, less common)

Transmission 4:

AW-4 (Aisin-Warner) 4-speed automatic (very popular, especially with 4.0L)

4Wd System:

Selec-Trac (Command-Trac NP231 or NP242 transfer case)

Automatic Transmission Fluid:

ATF+3 or equivalent (check specific model year for precise spec, e.g., Dexron II/III)

Manual Transmission Fluid:

GL-3 or GL-4 gear oil, 75W-90 or 80W-90 (check manual for specific gearbox)

📐 Dimensions

Wheelbase Short:

113.0 inches

Wheelbase Long:

120.0 inches

Bed Length Short:

6 feet

Bed Length Long:

7 feet

Curb Weight Approx:

3,500 - 4,000 lbs (depending on configuration)

Towing Capacity Max:

Up to 5,000 lbs (with appropriate engine and towing package)

Payload Capacity Max:

Up to 1,500 lbs

🛡️ Safety Features

NHTSA Ratings Era:

Safety testing standards were less rigorous than today. Specific ratings for this era may be limited.

Braking:

Front disc, rear drum brakes; optional ABS available on later models.

Traction Control:

Not available.

Airbags:

Driver-side airbag introduced in later model years (around 1990-1991).

Seatbelts:

Lap and shoulder belts (front), lap belts (rear, bench seat).

💡 Technology Features

Audio System:

Factory AM/FM radio, optional cassette player. Basic analog controls.

ABS:

Optional Anti-lock Braking System (ABS) available on some models and years.

Original Connectivity:

None (no provisions for Bluetooth, USB, or smartphone integration).

🔧 Maintenance

Oil Change Interval:

Every 3,000 - 5,000 miles or 3-6 months (depending on oil type and driving conditions).

Engine Tune Up:

Spark plugs, air filter, fuel filter typically every 30,000 - 60,000 miles. Timing chain inspection recommended.

Transmission Fluid Change:

Automatic: Every 30,000 - 50,000 miles. Manual: Every 50,000 - 100,000 miles.

Coolant Flush:

Every 30,000 - 50,000 miles or 2-3 years.

Engine Oil Type:

10W-30 or 10W-40 (check manual for specific viscosity based on temperature, often 5W-30 for the 4.0L).

Engine Oil Capacity:

4.0L I6: 5 quarts (with filter); 2.5L I4: 4.5 quarts (with filter).

Coolant:

Ethylene glycol-based antifreeze, 50/50 mix with distilled water.

Power Steering Fluid:

ATF Dexron II or III.

Engine Common Problems:

Cylinder head cracking (especially early 4.0L), oil filter adapter leaks, CPS (Crankshaft Position Sensor) failure, distributorless ignition system issues (Renix).

Transmission Common Problems:

AW-4 solenoid failures, manual clutch wear, potential for transfer case chain stretch or wear in high-mileage 4x4 models.

Suspension Common Problems:

Worn leaf springs (rear), sagging front coils, worn ball joints and tie rod ends due to off-road use.

Electrical Common Problems:

Wiring harness chafing, grounds issues, aging sensors, Renix ECU failures.

Body Common Problems:

Rust in common Jeep areas (rocker panels, floor pans, tailgate), door hinge wear.

📚 Vehicle History

Jeep Legacy:

Jeep has a long-standing heritage in producing rugged, capable off-road vehicles, dating back to its WWII origins. This DNA is evident in the Comanche's robust construction and available 4x4 systems.

Mj Introduction:

The Comanche (MJ) was introduced for the 1986 model year as Jeep's entry into the compact pickup truck market, designed to leverage the success of the Cherokee (XJ).

Key Updates:

Updates included introduction of the 4.0L engine, revised interior trim, optional driver airbag, and minor styling tweaks throughout its production run.

Production Years:

1986-1992

Manufacturing Plant:

Toledo, Ohio, USA

Production Volume:

Relatively low compared to major competitors, contributing to its niche appeal and collector status today.

🏆 Awards & Recognition

Off Road Capability:

Consistently praised for its off-road prowess, inheriting the Jeep brand's reputation for ruggedness and trail capability, often outperforming larger, body-on-frame competitors.

Value Proposition:

Recognized by enthusiasts as a capable and durable platform, especially the 4.0L models, offering excellent value as a classic off-road vehicle or workhorse.