🏷️ Basic Information

Make:

Jeep

Model:

Wrangler

Model Generation:

TJ

Year:

1998

Chassis Code:

TJ

👋 Introduction

Vehicle Segment:

Compact SUV / Off-Road Vehicle

Brand Positioning:

Iconic American off-road capability, ruggedness, and utilitarian design

Key Competitors 1998:

Toyota Land Cruiser (lower trims), Suzuki Vitara, Mitsubishi Montero Sport

Off Road Capability:

Solid front and rear axles, robust four-wheel-drive system (Command-Trac NV231 or optional Selec-Trac NV242), high ground clearance, short wheelbase

Design:

Classic Jeep grille, round headlights, removable doors and top (full-steel or soft top options)

Powertrain Options:

Durable inline-6 and inline-4 engine options, available manual and automatic transmissions

📋 Manual Details

Systems Covered:

Engine, Transmission, Drivetrain, Suspension, Steering, Brakes, Electrical System, HVAC, Body & Chassis, Emissions Control, Troubleshooting, Diagnostics, Routine Maintenance, Specifications, Wiring Diagrams

Estimated Page Count:

1500+

Type:

Factory Service Manual (FSM) / Repair Manual

Language:

English

Format:

Digital Download (PDF)

📖 Manual Coverage

Engine Mechanical:

Detailed overhaul procedures, component testing, timing, lubrication, cooling system, fuel system, exhaust system

Engine Performance:

Ignition system diagnosis and repair, fuel injection operation and troubleshooting, emissions control systems

Transmission Manual:

Service and repair of AX-5 and NV3550 manual transmissions, clutch system, shift linkage

Transmission Automatic:

Service and repair of 30RH and 42RE automatic transmissions, torque converter, valve body, shift control

Drivetrain:

Front and rear axle service (Dana 30, Dana 35), differential overhaul, transfer case (NP231) service, driveshaft maintenance

Suspension:

Front and rear suspension component replacement (coil springs, shocks, control arms), alignment specifications

Steering:

Power steering system diagnosis and repair, steering gear, tie rod ends, steering column

Brakes:

Front disc brake service, rear drum brake service (or optional rear discs), ABS system diagnosis (if equipped), brake hydraulic system

Electrical System:

Battery, charging system (alternator), starting system (starter), lighting system, accessory circuits, fuses, relays

HVAC:

Air conditioning system service, heater core replacement, blower motor, climate controls

Body Chassis:

Body panel repair, door mechanisms, interior trim, convertible top service, frame inspection and repair

Emissions Control:

Catalytic converter, oxygen sensors, EGR system, evaporative emission control system

Maintenance:

Oil change intervals, filter replacement, fluid checks and changes, spark plug replacement, belt inspection and replacement, tire rotation

Troubleshooting:

Systematic diagnostic procedures for common and uncommon issues, symptom-based troubleshooting guides

Repair:

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

Diagnostics:

Diagnostic Trouble Codes (DTCs), on-board diagnostics (OBD-II) information, electrical troubleshooting using schematics

Specifications:

Torque specifications, clearances, fluid capacities, electrical data, alignment angles, tire pressures

Depth:

Comprehensive coverage from basic maintenance to full engine and transmission rebuilds, including advanced diagnostic techniques and wiring diagrams

📊 Manual Specifications

File Type:

PDF

Searchability:

Fully searchable text content for quick information retrieval

Print Quality:

High-resolution scans of original factory documentation, allowing for clear printing of diagrams and text

Binding:

N/A (Digital Download)

Paper:

N/A (Digital Download)

⚙️ Engine Specifications

Engine 1:

4.0L OHV Inline-6 (High Output)

Engine 1 Code:

242 cu in (3952 cc)

Engine 1 Horsepower:

182 hp @ 4600 rpm

Engine 1 Torque:

220 lb-ft @ 3200 rpm

Engine 2:

2.5L OHV Inline-4

Engine 2 Code:

150 cu in (2464 cc)

Engine 2 Horsepower:

118 hp @ 4700 rpm

Engine 2 Torque:

135 lb-ft @ 3250 rpm

Compression Ratio 4.0L:

8.8:1

Bore X Stroke 4.0L:

3.875 in x 3.414 in

Fuel Delivery:

Multi-port Fuel Injection (MPI)

Fuel Type:

Unleaded Gasoline (87 Octane Recommended)

🔧 Transmission

Transmission Standard Short Wheelbase:

5-speed Manual (AX-5)

Transmission Standard Long Wheelbase:

6-speed Manual (NV3550) - Introduced mid-year for some models

Transmission Optional:

4-speed Automatic (30RH or 42RE)

Transfer Case Standard:

New Process NP231 Command-Trac (Part-Time 4WD)

Transfer Case Optional:

New Process NP242 Selec-Trac (Full-Time 4WD option)

📐 Dimensions

Wheelbase Short Wheelbase:

93.4 inches (2372 mm)

Wheelbase Long Wheelbase:

103.4 inches (2626 mm)

Length Short Wheelbase:

151.4 inches (3845 mm)

Length Long Wheelbase:

161.4 inches (4100 mm)

Width:

66.7 inches (1694 mm)

Height:

65.4 inches (1661 mm) (Hardtop)

Curb Weight Approx:

3,100 - 3,500 lbs (1406 - 1588 kg)

🛡️ Safety Features

NHTSA Rollover Resistance:

3/5 stars (for most configurations)

ABS:

Available front disc / rear drum brakes with optional Anti-lock Braking System (ABS)

Airbags:

Driver and passenger front airbags

Rollover Protection:

Integrated roll cage structure within the body

💡 Technology Features

Radio:

AM/FM stereo with cassette player, optional CD player, basic speaker system

ABS:

Optional ABS available on front wheels

🔧 Maintenance

Oil Change Interval:

Every 3,000 miles (4,800 km) or 3 months (whichever comes first) under normal conditions; 7,500 miles (12,000 km) or 6 months under severe conditions (refer to manual for specifics)

Engine Oil Filter Replacement:

With every oil change

Spark Plug Replacement 4.0L:

Approx. 100,000 miles (160,000 km)

Transmission Fluid Change Manual:

Check every 30,000 miles (48,000 km), change as needed

Transmission Fluid Change Automatic:

Every 30,000 miles (48,000 km) or 24 months

Engine Oil Spec:

API SG or higher, SAE 10W-30 (check owner's manual for climate-specific recommendations)

Engine Coolant Spec:

Chrysler/Mopar OAT (Organic Additive Technology) or HOAT, 50/50 mix with distilled water

Brake Fluid Spec:

DOT 3

Transfer Case Fluid Spec Np231:

Mopar ATF+4 (or equivalent Dexron III/Mercon)

Automatic Transmission Fluid Spec:

Mopar ATF+4 (or equivalent Dexron III/Mercon)

Common Problems 1998 Wrangler:

Cracked exhaust manifolds (4.0L engine), radiator leaks, heater core failures, rear main seal leaks (4.0L), door hinge rust, sway bar link wear, "death wobble" (requires careful diagnosis of suspension and steering components).

📚 Vehicle History

Jeep Legacy:

Direct descendant of military vehicles dating back to World War II, known for unparalleled off-road prowess

Tj Introduction:

The TJ generation replaced the YJ Wrangler, bringing significant improvements in ride comfort, handling, and refinement while retaining its core off-road identity. Key change was the return to round headlights and the adoption of coil springs for all four wheels.

Production Era:

1997-2006

Manufacturing Plant:

Toledo, Ohio, USA

🏆 Awards & Recognition

Off Road Awards:

Consistently recognized for its off-road capabilities by automotive publications and enthusiasts; considered a benchmark for its class in off-road performance.