Segment:
Compact SUV / Off-road vehicle
Key Selling Points:
Off-road capability, iconic design, convertible options, ruggedness
Competitors 2003:
Toyota Tacoma (4x4), Nissan Xterra, Ford Explorer Sport Trac
Jeep Wrangler Tj Distinction:
Solid front axle, coil spring suspension, removable doors and top, short wheelbase for maneuverability
Value For Owners:
Empowers owners to perform maintenance and repairs, saving costs and extending vehicle life
Engine:
Engine mechanical, lubrication, cooling, fuel delivery, ignition, emissions, diagnostics, overhaul
Transmission:
Manual transmission (NV3550), Automatic transmission (42RLE), transfer case (NV241OR 'Rubicon' / NV135 'Sport/Sahara'), clutch, driveline
Brakes:
Front disc, rear disc (standard for TJ), ABS (if equipped), hydraulic system, parking brake
Suspension Steering:
Front and rear solid axles, coil springs, shock absorbers, steering gear, power steering system, control arms, linkages
Electrical:
Battery, charging system, starting system, lighting, instrumentation, power distribution, body electrical, chassis electrical, wiring diagrams
Body:
Body construction, interior trim, exterior trim, doors, hood, windshield, seats, soft top/hardtop systems, frame
HVAC:
Heating, ventilation, air conditioning system, components, service, refrigerant handling
Safety Features:
Airbags (if equipped), seat belts, child seat anchors
Maintenance:
Scheduled maintenance, fluid changes, filter replacements, inspections, lubrication
Diagnostics:
Troubleshooting procedures, diagnostic trouble codes (DTCs), symptom-based diagnostics, electrical system diagnosis
Repair:
Step-by-step repair instructions for all major components and systems, component removal and installation, assembly and disassembly
Overhaul:
Engine rebuild, transmission overhaul, axle rebuild
Adjustments:
Wheel alignment, clutch adjustment, brake adjustments, idle speed adjustment
Depth:
Comprehensive, from basic maintenance to complete engine/transmission rebuilds and advanced electrical diagnostics
Diagnostic Tools:
Includes information on required diagnostic tools, scan tools, and testing equipment
Specifications Data:
Torque specifications, clearances, tolerances, fluid capacities, electrical specifications, component data
Engine Code:
4.0L Inline-6 (PowerTech)
Engine Displacement:
3952 cc (241 cubic inches)
Bore X Stroke:
3.878 in x 3.578 in (98.5 mm x 90.9 mm)
Horsepower Net:
190 hp @ 4600 rpm
Torque Net:
235 lb-ft @ 3200 rpm
Fuel Delivery:
Sequential multi-port fuel injection (MPI)
Fuel Type:
Unleaded gasoline (87 octane recommended)
Optional Engine:
2.4L Inline-4 (97 hp @ 4800 rpm, 135 lb-ft @ 3200 rpm) - Less common for 2003 TJ
Engine Management:
Chrysler's NGC (Next Generation Controller) or similar OBDI/II compliant system
Transmission Type:
NV3550 5-speed manual transmission
Transmission Type:
42RLE 4-speed automatic transmission
Transfer Case Rubicon:
NV241OR 'Dana 44 Heavy Duty' with 4.0:1 low-range ratio
Transfer Case Sport Sahara:
NV135 Command-Trac 2-speed transfer case with 2.72:1 low-range ratio
Manual Transmission Fluid:
ATF+4 (MS-9602) or equivalent, 2.3 quarts capacity
Automatic Transmission Fluid:
ATF+4 (MS-9602) or equivalent, 7.4 quarts capacity
Transfer Case Fluid:
ATF+4 (MS-9602) or equivalent, 2.0 quarts capacity
Oil Change Interval:
Every 5,000 miles (8,000 km) or 6 months, whichever comes first
Air Filter Replacement:
Every 15,000 miles (24,000 km) or 12 months
Spark Plug Replacement:
Every 100,000 miles (160,000 km) for iridium-tipped plugs
Engine Oil Type:
SAE 10W-30 API SJ or SL certified
Engine Oil Capacity:
5.0 quarts (4.7 liters) with filter for 4.0L engine
Coolant Type:
Chrysler/Mopar OAT (Organic Additive Technology) antifreeze or equivalent (Pentofrost G11/G12 compatible)
Coolant Capacity:
Approx. 11.2 quarts (10.6 liters) for 4.0L engine
Common Issues:
Oil filter housing gasket leaks (4.0L), rear main seal leaks, clutch wear (manual), heater core issues, exhaust manifold cracks (early 4.0L models)
Off Road Considerations:
U-joint wear, differential seal leaks, suspension component stress
