Positioning:
The 1991 Jeep Cherokee XJ was a highly capable and popular compact SUV, known for its ruggedness, off-road prowess, and unibody construction, offering a blend of utility and comfort.
Competitors:
Competed with vehicles like the Ford Bronco II, Chevrolet S-10 Blazer, and Toyota 4Runner.
Unibody Construction:
Pioneering unibody construction for an SUV, offering lighter weight and improved ride quality compared to body-on-frame rivals.
4X4 Capability:
Renowned for its capable 4x4 systems, making it a favorite for off-roading and adverse weather conditions.
Value Proposition:
Provides technicians and owners with the exact, authoritative information needed for accurate and efficient maintenance and repair, directly from the source.
Engine:
Detailed diagnostics, repair procedures, and specifications for all available 1991 XJ engines.
Transmission:
Coverage for both automatic (e.g., AW4) and manual transmissions (e.g., AX-4, AX-15), including overhaul and diagnostics.
Drivetrain:
Front and rear axles, differentials, transfer cases (e.g., NP231 Command-Trac, NP242 Selec-Trac), driveshafts, and CV joints.
Brakes:
Front disc and rear drum brake systems, hydraulic lines, master cylinder, power booster, parking brake.
Suspension:
Front leaf spring or coil spring suspension, rear leaf spring suspension, shock absorbers, bushings, steering linkage.
Steering:
Power steering system, steering gear, steering column, tie rods, ball joints.
Electrical:
Complete wiring diagrams, component testing, starter, alternator, battery, ignition system, lighting, instruments, body electrical.
Fuel System:
Fuel tank, fuel pump, fuel injectors, fuel pressure regulator, evaporative emissions control (EVAP).
Cooling System:
Radiator, water pump, thermostat, cooling fan, heater core, climate control.
Exhaust System:
Exhaust manifold, catalytic converter, muffler, pipes, emission controls.
Body And Frame:
Body panels, doors, windows, interior trim, chassis and frame inspection, rust repair.
HVAC:
Air conditioning system, heating system, blower motor, refrigerant cycle, diagnostic procedures.
Maintenance:
Regular service intervals, oil changes, filter replacements, fluid checks and changes, lubrication.
Diagnostics:
Systematic troubleshooting guides for common and complex issues, fault code interpretation (OBD-I).
Repair:
Step-by-step instructions for component removal, installation, and overhaul for all major vehicle systems.
Special Tools:
Identification and usage of specialized tools required for specific repair and maintenance procedures.
Depth:
Comprehensive, covering everything from basic fluid checks to complete engine and transmission rebuilds, including detailed electrical schematics.
Engine Option 1:
4.0L (242 cu in) AMC I6 OHV
Engine Option 2:
2.5L (150 cu in) AMC I4 OHV (less common for later XJ models, but possible).
4.0L Horsepower:
Approx. 177 hp @ 4700 rpm (1991 figures).
4.0L Torque:
Approx. 220 lb-ft @ 3200 rpm (1991 figures).
Injection Type:
Multi-point Fuel Injection (MPFI)
4.0L Block Material:
Cast Iron
ECM Type:
OBD-I (On-Board Diagnostics, First Generation)
Transmission Option 1:
AW4 (4-speed Automatic)
Transmission Option 2:
AX-4 (4-speed Manual) or AX-15 (5-speed Manual) - check specific vehicle build.
Aw4 Features:
Electronically controlled automatic transmission with overdrive, known for reliability.
Automatic Transmission Fluid:
Chrysler ATF+3 (or equivalent like Dexron III/Mercon)
Aw4 Capacity:
Approx. 6.5 quarts (6.2 L) for a fluid change, more for overhaul.
Oil Change Interval:
Every 3,000 miles or 3 months (typical for the era).
Transmission Service:
Every 30,000-60,000 miles or as per manual recommendations, including filter replacement.
Coolant Flush:
Every 2 years or 30,000 miles.
Engine Oil Type:
10W-30 or 10W-40 (refer to manual for exact viscosity based on climate).
Coolant Type:
Ethylene glycol-based antifreeze (e.g., Mopar 50/50 mixture).
Cracked Cylinder Heads:
The 4.0L inline-six, while generally robust, can be susceptible to cracked cylinder heads over time due to heat cycles, especially if maintenance is neglected.
Radiator Leaks:
Older radiators can develop leaks or become clogged, affecting cooling performance.
Leaf Spring Sag:
Rear leaf springs can sag over time, particularly on heavily used or loaded vehicles, affecting ride height and handling.
Oil Filter Adapter Leaks:
The oil filter adapter housing on the 4.0L can develop leaks.
Jeep Legacy:
Jeep has a long-standing reputation for ruggedness and off-road capability, established with its military origins.
Xj Introduction:
The XJ Cherokee was introduced for the 1984 model year, revolutionizing the SUV market with its unibody design.
1991 Updates:
The 1991 model year saw minor updates, often including revised interior trim and potentially subtle drivetrain refinements.
Production Span:
The XJ Cherokee was produced from 1984 to 2001, making the 1991 model part of a long and successful run.
Manufacturing Location:
Primarily manufactured in Toledo, Ohio, USA.
