🏷️ Basic Information

Make:

Jeep

Model:

Wrangler

Year:

1998

Generation:

TJ

Chassis Code:

TJ

👋 Introduction

Positioning:

The 1998 Jeep Wrangler TJ represented a significant evolution from its YJ predecessor, offering a coil-spring suspension for improved ride comfort and handling, while retaining its iconic off-road capability. This manual caters to owners and technicians seeking to maintain, diagnose, and repair this robust 4x4 vehicle.

Competitors:

Direct competitors included the Toyota Land Cruiser (FJ series), Nissan Pathfinder, Ford Bronco, and Chevrolet Blazer. The Wrangler TJ distinguished itself with its dedicated off-road focus and open-air design.

Vehicle Attributes:

Renowned off-road prowess, coil-spring suspension (Quadra-Coil), iconic styling, available 4.0L 'Power Tech' inline-six engine, durable construction.

Value Proposition:

This comprehensive service repair manual empowers users to perform a wide range of maintenance and repair tasks, saving time and money on professional services and ensuring the longevity and optimal performance of their 1998 Jeep Wrangler.

📋 Manual Details

Primary Engine:

4.0L Inline 6-Cylinder (OHV)

Optional Engine:

2.5L Inline 4-Cylinder (OHV)

Estimated Pages:

Over 1500

Type:

Factory Service Manual (FSM)

Language:

English

Format:

Digital Download (PDF)

📖 Manual Coverage

Powertrain:

Engine mechanical, fuel system, cooling system, ignition system, exhaust system, transmission (manual & automatic), transfer case, drivetrain (axles, driveshafts, differentials)

Chassis:

Suspension (front & rear), steering system, braking system (front disc, rear drum/disc options), wheels, tires

Electrical:

12V electrical system, battery, charging system, starting system, lighting, instruments, gauges, wipers, washers, horn, power accessories, body control modules (BCM), fuses, relays, wiring diagrams

Body:

Body construction, exterior panels, interior trim, seats, doors, hood, tailgate, convertible top, glass, weatherstripping

HVAC:

Heating, Ventilation, and Air Conditioning (HVAC) system diagnosis and repair

Maintenance:

Scheduled maintenance, oil changes, filter replacements, fluid checks and changes, lubrication, battery maintenance, tire rotation

Repair:

Engine overhaul, transmission overhaul, brake system repair, suspension component replacement, steering system repair, electrical component diagnosis and replacement, body panel repair

Diagnostics:

Troubleshooting guides, diagnostic trouble codes (DTCs) interpretation, symptom-based troubleshooting, electrical system diagnostics, mechanical system diagnostics

Specifications:

Torque specifications, clearances, fluid capacities, electrical values, emissions data

Special Tools:

Identification and usage of specialized tools required for specific repairs and adjustments

Depth:

Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds, advanced electrical diagnostics, and bodywork.

📊 Manual Specifications

File Type:

PDF

Searchable Text:

Yes

Printable:

Yes

Image Resolution:

High resolution, suitable for clear viewing of diagrams and illustrations

Binding:

N/A (Digital Download)

Paper Quality:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Name:

4.0L Power Tech Inline 6-Cylinder

Engine Code:

ERH (typically)

Displacement:

3960 cc (241.7 cu in)

Bore X Stroke:

3.875 in x 3.562 in (98.4 mm x 90.5 mm)

Compression Ratio:

8.8:1

Horsepower:

182 hp @ 4,600 rpm

Torque:

220 lb-ft @ 3,200 rpm

Valvetrain:

Overhead Valve (OHV), 12 valves (2 per cylinder)

Block Material:

Cast Iron

Cylinder Head Material:

Cast Iron

Engine Name:

2.5L Power Tech Inline 4-Cylinder

Engine Code:

ENH (typically)

Displacement:

2469 cc (150.6 cu in)

Horsepower:

119 hp @ 4,600 rpm

Torque:

145 lb-ft @ 3,200 rpm

Fuel Delivery:

Electronic Fuel Injection (EFI) with Multi-Port Injection (MPI)

Recommended Fuel:

87 Octane Unleaded Gasoline

Fuel Tank Capacity:

15 US gallons (approx.)

🔧 Transmission

Type:

NV3550 5-Speed Manual Transmission

Type:

42RLE 4-Speed Automatic Transmission

Type:

NP231 Command-Trac (Part-Time, 2.72:1 low range)

Gear Ratios Manual Nv3550:

1st: 4.01, 2nd: 2.32, 3rd: 1.42, 4th: 1.00, 5th: 0.79, Reverse: 3.55

Fluid Type Manual:

Mopar Manual Transmission Lubricant (or equivalent, consult manual for specifics)

Fluid Type Automatic:

ATF+3 (Chrysler Material Number 04874464)

📐 Dimensions

Wheelbase:

93.4 inches (2372 mm)

Length:

151.3 inches (3843 mm)

Width:

66.5 inches (1689 mm)

Height:

70.5 inches (1791 mm) (soft top)

Ground Clearance:

10.5 inches (267 mm) (approx.)

Curb Weight:

3,046 - 3,365 lbs (1382 - 1526 kg), depending on configuration

Gross Vehicle Weight Rating Gvwr:

4,200 lbs (1905 kg)

Towing Capacity:

2,000 lbs (907 kg) (properly equipped)

🛡️ Safety Features

NHTSA Rollover Resistance:

3-star (may vary)

Brakes:

Front ventilated disc brakes, Rear drum brakes (standard on most models), optional rear disc brakes

Anti Lock Brakes ABS:

Optional, typically on 4-wheel disc brake systems

Airbags:

Driver and passenger airbags

Seat Belts:

Three-point front seat belts, lap belts in rear

💡 Technology Features

Audio System:

AM/FM radio with cassette player (optional CD player), 4-speaker system.

Cruise Control:

Optional

Anti Theft:

Factory alarm system (optional)

Connectivity Features:

Limited by modern standards; primarily focused on basic vehicle functions.

🔧 Maintenance

Oil Change 40L Engine:

Every 3,000-5,000 miles (5,000-8,000 km) or 6 months, whichever comes first (recommend using synthetic blend for longevity).

Oil Change 25L Engine:

Every 3,000-5,000 miles (5,000-8,000 km) or 6 months, whichever comes first.

Engine Coolant Flush:

Every 30,000 miles (48,000 km) or 2 years.

Transmission Fluid Change Automatic:

Every 30,000-60,000 miles (48,000-96,000 km) depending on driving conditions.

Transmission Fluid Change Manual:

Every 60,000-100,000 miles (96,000-160,000 km).

Transfer Case Fluid Change:

Every 60,000-100,000 miles (96,000-160,000 km).

Differential Fluid Change:

Every 60,000-100,000 miles (96,000-160,000 km).

Spark Plug Replacement 40L:

Every 60,000-100,000 miles (100,000-160,000 km) depending on plug type (e.g., copper vs. platinum).

Engine Oil 40L:

SAE 10W-30 (API SJ or higher), 5.9 US quarts (5.6 liters) with filter.

Engine Oil 25L:

SAE 10W-30 (API SJ or higher), 4.5 US quarts (4.3 liters) with filter.

Coolant:

Chrysler OAT (Organic Acid Technology) or HOAT (Hybrid Organic Acid Technology) antifreeze, typically a 50/50 mix with distilled water. Mopar Antifreeze/Coolant 10-Year/100,000 Mile Formula.

Brake Fluid:

DOT 3

Power Steering Fluid:

ATF+3 or Mopar Power Steering Fluid

Common Problems:

Cracking of the exhaust manifold (4.0L), valve cover gasket leaks, rear main seal leaks, front sway bar disconnect linkage issues, differential seal leaks, ignition coil issues, potential for death wobble (requires proper diagnosis and alignment).

📚 Vehicle History

Jeep Legacy:

Jeep's heritage dates back to World War II with the Bantam GP, Willys MB, and Ford GPW, establishing a legacy of rugged, go-anywhere capability. The Wrangler lineage, starting with the CJ series, directly inherits this DNA.

Tj Generation:

The TJ generation (1997-2006) marked a significant departure from the YJ with the introduction of coil springs, significantly improving on-road manners. The 1998 model year was early in the TJ's lifecycle, establishing its fundamental platform.

Manufacturing Location:

Toledo Complex, Toledo, Ohio, USA

🏆 Awards & Recognition

Off Road Capability:

Consistently praised by off-road enthusiasts and publications for its superior articulation, ground clearance, and robust drivetrain.

Utility:

Awarded for its go-anywhere utility and iconic design by various automotive critics and consumer groups throughout its production run.