🏷️ Basic Information Identification Make: Jeep Model: Wrangler Year: 2003 Codes Internal Model Code: TJ 👋 Introduction Market Position Segment: Compact SUV / Off-Road Vehicle Key Selling Points: Off-road capability, iconic design, open-air experience Competitive Analysis Direct Competitors 2003: Toyota 4Runner, Nissan Xterra, Ford Explorer (though Explorer was larger), Suzuki Vitara Key Features Vehicle Design: Body-on-frame construction, solid axles (front and rear), removable doors and top Key Features Manual Value Proposition: Enables DIY repairs, saving significant labor costs compared to professional workshops. Target Audience: Jeep Wrangler owners with basic to intermediate mechanical aptitude, DIY enthusiasts, off-roaders. 📋 Manual Details Coverage Areas Primary Coverage: Full Service and Repair Secondary Coverage: Troubleshooting, Diagnostics, Electrical Schematics, Specifications Page Count Estimated Pages: 1000+ Manual Type Type: Factory Service Manual / Workshop Manual Language Language: English Format Format: Digital (likely PDF, searchable) 📖 Manual Coverage Systems Covered Engine: Engine Overhaul and Rebuilding, Engine Performance, Timing Belt Service Procedures, Firing Orders Transmission: Transmission Removal and Installation, Transmission In-Car Servicing Chassis: Front End and Alignment, Suspension, U-Joint and CV-Joint Service Procedures Brakes: Brake Servicing Procedures, Complete Torque Specifications (relevant to brakes) Electrical: Complete Wiring Diagrams, Vacuum Diagrams Climate Control: Air Conditioning Service and Capacities Procedures Included Diagnostic Procedures: Troubleshooting and Diagnostics, Computer Diagnostic Trouble Tree Charts Repair Procedures: Step-by-step repair explanations for all major vehicle systems Maintenance Procedures: Routine maintenance tasks, fluid changes, component replacement Technical Depth Depth: Comprehensive (from basic maintenance to major component overhaul and rebuilding) Illustrations Diagrams: Detailed illustrations, diagrams, depth illustrations 📊 Manual Specifications File Format File Type: Digital (PDF recommended for searchability and printing) Print Quality Quality: High-resolution for clear diagrams and text Binding Type Binding: N/A (Digital) Paper Type Paper: N/A (Digital) ⚙️ Engine Specifications Primary Engine Engine Code And Type: 4.0L Inline-6 (OHV) - AMC/Chrysler 242 Displacement: 3957 cc (242 cubic inches) Performance Horsepower: Approx. 190 hp @ 4600 RPM Torque: Approx. 235 lb-ft @ 3200 RPM Fuel System Fuel Delivery: Multi-Point Fuel Injection (MPI) Recommended Fuel: 87 Octane Unleaded Gasoline Engine Overhaul Engine Block Material: Cast Iron Cylinder Head Material: Cast Iron Timing Belt Service Timing Mechanism: Timing Chain (no belt to replace on the 4.0L) Firing Orders Firing Order: 1-5-3-6-2-4 Troubleshooting Common Engine Issues 2003: Cracked cylinder heads (less common in later 4.0L versions), intake manifold gasket leaks, CPS (Crankshaft Position Sensor) failure. 🔧 Transmission Standard Transmission Type: NV3550 5-speed Manual Transmission Optional Transmission Type: 42RLE 4-speed Automatic Transmission Features Transfer Case: NV241OR 2-speed Off-Road Transfer Case (Rock-Trac on Rubicon models, NP231 for others) Fluid Specifications Manual Transmission Fluid: Axle & Manual Transmission Lubricant, API GL-3, SAE 75W-90 (e.g., Mopar NV3550 Fluid, Red Line MT-90) Automatic Transmission Fluid: ATF+4 (MS-9602) Transfer Case Fluid: Mopar Multi-Purpose Gear Lubricant, API GL-5, SAE 75W-90 (or equivalent) 📐 Dimensions Exterior Wheelbase 2 Door: 93.4 inches (2372 mm) Wheelbase 4 Door Unlimited: 103.4 inches (2626 mm) - *Note: The 2003 model year primarily featured the 2-door.* Length 2 Door: 151.4 inches (3845 mm) Weights Curb Weight 2 Door: Approx. 3,400 - 3,700 lbs (1542 - 1678 kg) 🛡️ Safety Features Ratings NHTSA Front Impact Driver: 4 Stars (2003 Model Year) NHTSA Front Impact Passenger: 4 Stars (2003 Model Year) Active Features Braking System: Front Disc, Rear Drum (standard for most trims) ABS: Optional on some trims, standard on others (typically front wheels only for this era). Passive Features Airbags: Driver and Passenger Front Airbags Seat Belts: Three-point front seat belts, lap belts in rear 💡 Technology Features Infotainment Audio System: Basic AM/FM/CD player, optional premium sound system. Limited integrated technology typical for the era. Driver Assistance Features 2003: Minimal driver assistance features; primarily focused on mechanical capability rather than electronic aids. Connectivity Features 2003: No integrated Bluetooth or navigation. Antenna for radio is standard. 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,000-5,000 miles or 6 months, whichever comes first (refer to manual for exact recommendation based on driving conditions). Transmission Fluid Change Manual: Approx. every 30,000-60,000 miles, or as specified in the manual. Transmission Fluid Change Automatic: Every 30,000-45,000 miles (ATF+4 is often considered a longer-life fluid). Coolant Flush: Every 2 years or 30,000-50,000 miles. Fluid Specifications Engine Oil Specification: API Certified SAE 10W-30 (e.g., Mopar 5W-30 Synthetic if using a higher grade, but 10W-30 is standard). Engine Oil Capacity: Approx. 5 quarts (4.7 liters) with filter change for the 4.0L. Coolant Type: Ethylene Glycol Antifreeze/Coolant, Mopar HOAT (Hybrid Organic Acid Technology) or equivalent. Known Issues Common Issues Tj: Leaks (oil, coolant, transmission), rear main seal leaks, differential seal leaks, exhaust manifold cracks (on older 4.0L), rust (especially on frame and body tub), clutch wear (manual transmission), alternator and power steering pump failures. Brake Specifications Front Brakes: Ventilated Disc Rear Brakes: Solid Disc (on Rubicon), Drum Brakes (on other trims) Torque Specifications Wheel Lug Nuts: 95 lb-ft (129 Nm) U Joint Cv...