🏷️ Basic Information

Make:

Mercedes-Benz

Model:

G-Class

Model Code:

W463

Year:

1991

👋 Introduction

Target Audience:

Mercedes-Benz G-Class (W463) owners, DIY mechanics, independent repair shops

Value Proposition:

Provides factory-level, vehicle-specific repair and maintenance data, surpassing generic repair guides.

Instruction Style:

Complete step-by-step instructions with diagrams, illustrations, and schematics.

Usability:

Single, easy-to-use PDF manual, printable pages for workshop use, no more physical manual wear and tear.

Diagnostic Capability:

Enables in-depth diagnosis and repair, reducing reliance on dealerships for routine issues.

Illustrations:

High-quality, detailed illustrations and diagrams that clearly show component location, orientation, and assembly order.

📋 Manual Details

Primary Coverage:

Full Service, Maintenance, Repair, Diagnostics

Scope:

All Models & All Repairs A-Z

Estimated Pages:

Extensive (Implied by comprehensive coverage)

Type:

Service and Repair Manual

Source:

Factory Service Information

Language:

English

Digital Format:

PDF

📖 Manual Coverage

Powertrain:

Engine, Fuel Service, Emission Control, Intake/Exhaust/Cooling, Lube, Ignition, Starting/Charging, Auto Transmission, Manual Transmission, Transfer Case, Differential, Axle

Chassis:

Suspension, Tire & Wheel, Brake Control, Brakes, Parking Brake, Steering Column, Power Steering

Body & Electrical:

Air Conditioning, Supplemental Restraint System (SRS), Seat Belt, Engine Immobilizer, Cruise Control, Wiper & Washer, Door Locks, Meter/Audio/Visual, Horn, Windshield/Glass/Mirror, Instrument Panel, Seats, Engine Hood/Doors, Exterior & Interior, Electrical Systems, Multiplex/CAN Communication

Body And Frame:

Frame structure, body panel repair, door mechanisms, hinges, locks, glass replacement, and interior trim.

Lighting And Signals:

Headlights, taillights, turn signals, interior lighting, and associated wiring.

Maintenance:

Scheduled Maintenance, Fluid Changes, Filter Replacements, Inspections

Repair:

Component Removal & Installation, Overhauls, Adjustments, Diagnoses

Diagnostics:

Troubleshooting Guides, Symptom-Based Diagnosis, Diagnostic Trouble Codes (DTCs)

Torque Specifications:

Crucial torque values for all critical fasteners across engine, transmission, chassis, and suspension components.

Troubleshooting Charts:

Systematic guides for diagnosing faults based on symptoms, with cross-references to relevant sections.

Depth:

Factory-Level Detail, Step-by-Step Instructions, Comprehensive Diagrams and Illustrations

Diagnostics Detail:

Advanced Diagnostic Procedures, Wiring Schematics for Electrical Systems

Engine Rebuild:

Instructions for complete engine disassembly, inspection, and reassembly.

Transmission Overhaul:

Detailed procedures for automatic and manual transmission rebuilds, including component identification and assembly sequence.

📊 Manual Specifications

File Type:

PDF

Searchability:

PDF format allows for text searching of keywords and components.

Printability:

All pages printable, scalable images

Binding:

N/A (Digital Format)

Paper Quality:

N/A (Digital Format, printable on user's choice of paper)

Reader:

Adobe PDF Reader

Unzipping:

Winzip (or equivalent)

Operating Systems:

Windows (Vista32/64, XP, ME, 98, NT, 2000) and Mac

⚙️ Engine Specifications

Engine Type:

This manual covers various W463 engine configurations for 1991. Common engines include gasoline (e.g., M102 2.3L, M103 3.0L) and diesel (e.g., OM602 2.9L).

Horsepower Torque:

Specific figures vary by engine. The manual will detail Horsepower and Torque curves for each applicable engine.

Fuel Delivery:

Fuel Injection (likely Bosch KE-Jetronic or similar for gasoline, indirect injection for diesel). Manual details fuel pump, injectors, pressure regulator, and diagnostic procedures.

Fuel Filter Replacement:

Detailed instructions for locating and replacing the fuel filter, including necessary precautions.

Cooling Type:

Pressurized liquid cooling system. Manual covers radiator, fan, water pump, thermostat, hoses, and coolant specifications.

Oil System:

Forced lubrication. Manual details oil pump, oil filter, oil cooler (if equipped), and oil specifications (e.g., MB 229.1 or similar for the era).

🔧 Transmission

Type 1991:

Likely a 4-speed automatic or 5-speed manual transmission, depending on the specific G-Class variant. The manual covers both.

Gear Ratios:

The manual will provide detailed gear ratios for both manual and automatic transmissions fitted to the 1991 W463.

Transmission Options:

Details on available automatic and manual transmission variants for the 1991 model year.

Transmission Fluid:

Specifications and capacities for automatic transmission fluid (e.g., Dexron II or equivalent Mercedes-spec ATF) and manual transmission oil.

Transfer Case Operation:

Information on the G-Class's robust 4x4 system, including locking differentials (if applicable to the 1991 model), transfer case maintenance, and repair.

📐 Dimensions

Wheelbase:

Varies by specific G-Wagen body style (e.g., short wheelbase, long wheelbase). Manual will list for each variant.

Ground Clearance:

Significant ground clearance inherent to the G-Class design. Specific figures provided in manual.

Tire Size:

Common sizes for this era might include 205R16, 225/75R16, or similar. Manual will specify correct sizes for different trims/models.

Wheel Bolt Pattern:

Typically 5x112mm for Mercedes-Benz vehicles of this era. Manual will confirm.

Curb Weight:

Varies significantly by engine and body style, typically in the range of 4,400 - 5,000 lbs (approx. 2000-2300 kg).

Gross Vehicle Weight Rating:

Detailed GVWR for each model variant will be present in the manual.

🛡️ Safety Features

Crash Test Results:

Information on early safety standards and G-Class's robust chassis design; specific ratings from this era might be limited but structural integrity will be covered.

Braking System:

Details on front disc and rear drum (or all-disc on some variants) brakes, ABS (if equipped), and brake system diagnostics.

Airbags:

Supplemental Restraint System (SRS) coverage, including airbag sensors, control module, and SRS warning light troubleshooting.

Seat Belts:

Detailed information on seat belt mechanisms, pretensioners, and adjustment/repair procedures.

💡 Technology Features

Audio System:

Coverage for the factory radio and speaker system, including wiring and troubleshooting common audio issues.

ABS:

Detailed diagnostic and repair procedures for the Anti-lock Braking System (if equipped on the specific 1991 model).

Cruise Control:

System operation, adjustment, and troubleshooting for the cruise control system.

Multiplex Communication:

Explanation of the vehicle's multiplexed electrical system or early CAN communication protocols, and how to diagnose communication faults.

🔧 Maintenance

Oil Change Interval:

Typically every 7,500 miles or 12 months, but the manual will provide specific recommendations based on driving conditions.

Major Service Points:

Includes spark plugs, fuel filter, air filter, and transmission fluid/filter changes at specified intervals (e.g., 30,000 miles).

Engine Oil Grade:

Likely 10W-40 or 15W-40 API SG or higher, or a synthetic equivalent meeting MB specifications for the era. Manual confirms exact spec.

Coolant Type:

Proprietary Mercedes-Benz coolant or equivalent silicate-free antifreeze with long-life properties. Manual specifies the correct type and mix ratio.

Brake Fluid Type:

DOT 3 or DOT 4 brake fluid, as specified by Mercedes-Benz. Manual provides the precise specification.

Power Steering Fluid:

Specific hydraulic fluid type for the power steering system. Manual details the correct fluid and capacity.

Common Wear Items:

Referenced within the manual might include aging rubber hoses and seals, potential for minor electrical gremlins due to age, and differential lock actuator wear (if equipped).

Engine Specific Notes:

The manual will detail any specific maintenance or common issues for the M102, M103, or OM602 engines, such as valve adjustments or injector servicing.

📚 Vehicle History

Mercedes Benz Legacy:

Mercedes-Benz's reputation for robust engineering and luxury, applied to a rugged off-road platform.

W463 Introduction:

The W463 chassis was introduced in 1989 as a more refined and comfortable successor to the original W460/W461 G-Wagen, while retaining its legendary off-road capabilities.

Manufacturing Location:

Graz, Austria (in partnership with Magna Steyr).

🏆 Awards & Recognition

Offroad Capability:

While not a specific award, the G-Class is widely recognized for its exceptional off-road prowess, a testament to its engineering, which is detailed in the manual.