2002 Jeep Grand Cherokee WG Factory Service Manual (P/N 81-370-02064)

This 4,472-page PDF covers the 2002 Jeep Grand Cherokee WJ/WG and centers on the WJ Service Manual identified as DaimlerChrysler Publication No. 81-370-02064. It is written for professional automotive technicians engaged in daily repair work; its DRB III routines, precision drivetrain setup, and special-tool requirements assume workshop-level experience.

• Document set: two-page cover and foreword; 2,199-page WJ Service Manual; 291-page 2.7L diesel supplement; and separate Gas Powertrain, Diesel Powertrain, Chassis, Transmission, Diesel Transmission, and Body diagnostic volumes of 410, 284, 74, 260, 170, and 782 pages respectively.
• Vehicle and powertrain coverage: Sport, Laredo, Limited, and Overland series codes; 4x2 and 4x4 LHD configurations; export and RHD material; 4.0L Power Tech I-6, 4.7L Power Tech V8 and H.O.-specific content, plus the 2.7L common-rail turbo-diesel.
• Engine repair: engine removal and installation, cylinder heads, camshafts, valve gear, timing drives, pistons, crankshafts, lubrication, cooling, fuel delivery, gasoline injection, diesel high-pressure injection, turbocharger, charge-air cooling, EGR, and emissions systems.
• Transmission and transfer-case work: 42RE, 545RFE, and W5J400 diagnosis and internal service, including torque converters, pumps, valve bodies or electrohydraulic units, clutch assemblies, geartrains, adjustments, and operational checks; NV242/NV242HD and NV247 disassembly and assembly procedures are included.
• Axle, suspension, steering, and brake service: 186FBI front and 198RBI/226RBA rear axles, standard, Trac-Lok, and Vari-Lok differentials, propeller shafts and Cardan joints, standard and Up-Country alignment, link/coil suspension, steering gear and pumps, base brakes, Teves ABS, hydraulic control unit, and bleeding procedures.
• Factory diagnostics: DTC- and symptom-based test trees for gasoline and diesel driveability, 42RE/545RFE and W5J400 controls, ABS, charging and starting, PCI-bus communication, airbags, Automatic Zone Control, power accessories, heated and memory seats, TPMS, SKIS, RKE, and vehicle theft systems, followed by repair verification tests.
• Electrical and body information: 8W wiring for power distribution, grounds, fuel/ignition, transmission control, ABS, restraints, HVAC, lighting, trailer tow, and power accessories, backed by connector pinouts, splice and ground locations, body opening dimensions, glass, doors, liftgate, seats, sunroof, trim, and structural repair data.

Mechanical Service Depth

The maintenance group provides factory service schedules, approved fluid types and capacities, fill/check locations, hoisting and jacking points, towing, and jump-starting information. Suspension procedures cover hub/bearing and axle-shaft service along with ball joints, control arms, track bars, stabilizer bars, springs, and shocks. Alignment data separates standard and Up-Country caster, camber, and toe specifications.

The axle chapters cover pinion-depth measurement, shim selection, differential-bearing preload, backlash, and gear-contact pattern interpretation for each axle family. Transmission material adds clutch-clearance and end-play checks, hydraulic pressure testing, band or shift-system adjustment, cooler flushing, Quick Learn and drive-learn routines, and model-specific fault isolation. Component torque charts, fluid capacities, pressure and electrical test data, wear limits, clearances, and alignment specifications are placed with the related assemblies.

Specified tools include the DRB III with probe 6801 and transmission simulator 8333, 4.7L timing-chain tools 8350 and 8515, axle flange spanner 6958, and 2.7L diesel camshaft lock 8929, crankshaft lock 8932, and timing-chain retainer 8931.

Diagrams and Diagnostic Support

Representative visual references include 545RFE hydraulic schematics, ring-and-pinion contact-pattern charts, 4.7L timing-chain alignment views, 8W-30 fuel/ignition wiring, 8W-35 antilock-brake wiring, and vehicle-communication schematics. The diagnostic books add component-location views, connector cavity and pin assignments, state charts, waveform examples, and no-code symptom testing where a stored DTC alone is not enough.

Repair Cautions and Scope

The differential procedures warn that excessive pinion-nut tightening can over-crush the collapsible spacer and damage the spacer or bearings; preload cannot be corrected by simply backing off the nut. In the 4.7L cylinder-head and camshaft work, uncontrolled crankshaft/camshaft movement or failure to restrain the timing-chain tensioners can damage valves, pistons, or the tensioner mechanism.

Coverage extends across the complete vehicle, combining mechanical repair procedures with system-level diagnostics. Safety sections address brakes, restraints, refrigerant, electrical isolation, hoisting, and road testing. Vehicle-rated lifting equipment and the prescribed support points are required before under-vehicle work, while airbag, ABS, A/C, and drivetrain procedures call for the relevant workshop precautions and service equipment.