🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W126 SE

Year:

1985

Generation Code:

Second Generation (1980-1991)

👋 Introduction

Target Audience:

Mercedes-Benz W126 owners, independent repair shops, DIY enthusiasts seeking professional-level repair information.

Value Proposition:

Provides the same comprehensive, vehicle-specific information used by dealership technicians, offering significant cost savings compared to dealership labor rates. Avoids generic repair advice.

Data Format:

Single, easy-to-use PDF file, eliminating the need for multiple physical books. Searchable content for quick information retrieval.

Accessibility:

Printable pages for use in the workshop. Ability to enlarge diagrams and print in larger formats.

📋 Manual Details

Primary Coverage:

Service, Repair, Maintenance, Diagnostics

Model Variants Covered:

All W126 SE models for 1985

Estimated Page Count:

Extensive (often 1000+ pages for factory manuals of this era)

Type:

Factory Service and Repair Manual (FSM)

Language:

English

Format:

PDF

📖 Manual Coverage

Engine:

Detailed diagnostics, overhaul, fuel injection (Bosch K-Jetronic/KE-Jetronic), ignition, cooling, lubrication, emission controls.

Transmission:

Automatic transmission (e.g., 4-speed 722.3) service, overhaul, diagnostics, and fluid specifications.

Brakes:

Hydraulic system, ABS (if equipped), calipers, rotors, master cylinder, brake fluid specifications, bleeding procedures.

Suspension Steering:

Front and rear suspension components, shock absorbers, springs, ball joints, bushings, power steering system, steering gear.

Electrical Systems:

Comprehensive wiring diagrams, lighting, starter, alternator, battery, instrument cluster, power windows, locks, climate control, audio systems.

Body Chassis:

Body panel removal/installation, doors, hood, trunk, interior trim, glass, seals, chassis lubrication.

Emission Control:

Exhaust Gas Recirculation (EGR), Oxygen sensors (if equipped), catalytic converter system, fuel evaporative emissions control.

Fuel Service:

Fuel pump, fuel filter replacement, fuel line diagnostics, fuel tank service, fuel pressure testing.

Ignition Starting Charging:

Spark plugs, ignition coils, distributor, starter motor, alternator, battery testing, and charging system diagnostics.

Drive Axle Differential:

Rear axle, differential service and fluid specifications, drive shafts, U-joints.

Tire Wheel:

Tire pressure recommendations, wheel torque specifications, wheel bearing service.

Steering Column:

Steering column adjustments, ignition switch replacement, steering lock mechanism.

Interior Exterior:

Door handle replacement, window regulator repair, seat adjustment mechanisms, exterior trim installation.

Instrument Panel:

Instrument cluster removal and repair, gauge diagnostics, warning lamp functions.

Wipers Washers:

Wiper motor, linkage, washer pump, and reservoir service.

Supplemental Restraint System:

Seat belt pre-tensioners and airbag system diagnostics and replacement (if equipped).

Climate Control HVACt:

Detailed procedures for HVAC system component testing and repair, including compressor, condenser, evaporator, and climate control unit.

Maintenance:

Scheduled maintenance intervals, fluid changes (oil, coolant, brake, transmission), filter replacements, tune-ups.

Diagnostics:

Troubleshooting guides, fault code identification (if applicable for the era), component testing procedures.

Repair Overhaul:

Detailed step-by-step instructions for major component repairs and complete overhauls (engine, transmission, brakes, etc.).

Technical Specifications:

Torque specifications, clearances, fluid capacities, electrical resistance values, alignment settings.

Engine Rebuild:

Complete engine overhaul procedures, including piston/ring replacement, bearing replacement, valve grinding, cylinder head gasket replacement.

Transmission Rebuild:

Detailed step-by-step instructions for automatic transmission disassembly, cleaning, inspection, and reassembly.

Wiring Schematics:

Comprehensive and detailed wiring diagrams for all electrical systems, critical for troubleshooting.

Depth:

Factory-level detail, covering everything from basic fluid checks to complete engine and transmission rebuilds. Includes diagnostic procedures used by authorized technicians.

Diagnostic Tools:

Mentions necessary special tools and diagnostic equipment used by technicians.

📊 Manual Specifications

Compatibility:

Windows (Vista 32/64, XP, ME, 98, NT, 2000) and Mac OS. Requires Adobe PDF Reader.

Searchability:

Searchable PDF text for quick access to specific topics or components.

Printability:

All pages are printable, allowing users to print specific sections or the entire manual. High-resolution images and diagrams.

Diagram Enhancement:

Ability to 'blow-up' (enlarge) images and diagrams for clarity during complex procedures.

Binding:

Digital (PDF). No physical binding.

Digital Format:

N/A (Digital)

⚙️ Engine Specifications

Engine Code Example:

M103 (2.6L) or M116 (3.8L) V8 (depending on specific SE variant for 1985)

Horsepower Estimate:

Approximately 150-180 HP (for 2.6L) or 200-230 HP (for 3.8L V8)

Torque Estimate:

Approximately 195-210 lb-ft (for 2.6L) or 230-260 lb-ft (for 3.8L V8)

Fuel Injection Type:

Bosch CIS-E (Continuous Injection System - Electronic) or KE-Jetronic.

Fuel Type:

Unleaded Gasoline (Premium)

Coolant Type:

Mercedes-Benz specification coolant (e.g., G48/50% Ethylene Glycol based)

🔧 Transmission

Transmission Type Standard:

4-speed Automatic Transmission (e.g., 722.3)

Transmission Type Optional:

Manual Transmission was rare or not offered on SE models in North America for 1985, but is covered if present in the manual.

Transmission Fluid Type:

MB Specification 236.3 or 236.7 Automatic Transmission Fluid (ATF).

📐 Dimensions

Wheelbase:

Approximately 2936 mm (115.6 inches)

Length:

Approximately 4995 mm (196.7 inches)

Curb Weight Estimate:

Approximately 1700-1800 kg (3750-4000 lbs)

Gross Vehicle Weight Rating Estimate:

Approximately 2250 kg (4960 lbs)

🛡️ Safety Features

Historical Safety Standards:

Designed to meet or exceed safety standards of the era, with a robust chassis and crumple zones. Specific numerical ratings from independent agencies might be limited for this vintage.

Antilock Brakes ABS:

Optional ABS (Anti-lock Braking System) available on some models.

Seat Belts:

Standard front seat belts, often with automatic tensioners. Rear seat belts standard.

Airbags:

Driver-side airbag became available later in the W126's lifecycle; unlikely to be standard on a 1985 SE model unless specified.

💡 Technology Features

Audio System:

Factory AM/FM stereo with cassette player, often with premium speaker options. Manual covers system diagnostics and repair.

Climate Control:

Automatic climate control (optional or standard depending on trim), manual covers system operation, diagnostics, and repair of A/C and heating components.

Instrument Cluster Features:

Includes diagnostics for odometer, tachometer, fuel gauge, temperature gauge, oil pressure warning light, etc.

Cruise Control:

Standard cruise control system, covered in detail for operation and troubleshooting.

Multiplex Communication:

Limited by modern standards; primarily conventional wiring. The manual may reference multiplex communication if used in specific control modules.

🔧 Maintenance

Oil Change Interval:

Typically every 15,000 km (9,000 miles) or 12 months, using synthetic oil.

Transmission Fluid Service:

Recommended every 50,000-60,000 km (30,000-40,000 miles).

Coolant Change Interval:

Every 2-3 years or as specified.

Engine Oil Specification:

API SG or higher, SAE 15W-40 or 10W-40 (depending on climate, consult manual for exact spec)

Brake Fluid Specification:

DOT 3 or DOT 4.

Common Wear Items:

Fuel distributor seals, distributor O-rings, fuel accumulator, vacuum hoses, climate control blower motor, suspension bushings, headliner sagging.

Electrical Gremlins:

Wiring harness degradation (especially under-dash and engine bay) is common with age; corrosion in connectors.

Fuel System Aging:

Potential for aging fuel lines and seals, common in vehicles of this age, covered by the manual for replacement.

📚 Vehicle History

Brand Reputation:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, durability, and safety.

W126 Introduction:

The W126 S-Class was introduced in 1979 as the successor to the W116. It represented a significant advancement in automotive design, engineering, and safety.

W126 Updates:

The 1985 model year saw the introduction of the M103 2.6L inline-6 engine and updates to the K-Jetronic fuel injection system (KE-Jetronic), often referred to as the 'facelift' or 'late' W126, although the major facelift occurred in 1985.

W126 Legacy:

The W126 is considered a modern classic, celebrated for its build quality, timeless design, and comfort.

Manufacturing Location:

Sindelfingen, West Germany