🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W126 SEL

Year:

1985

👋 Introduction

Positioning:

The W126 SEL represented Mercedes-Benz's flagship luxury sedan in 1985, offering unparalleled comfort, build quality, and advanced technology for its time. This manual positions itself as the definitive guide for owners and technicians aiming to maintain and repair this prestigious vehicle.

Competition:

Competed with other high-end luxury sedans of the era such as the BMW 7 Series, Cadillac Sedan de Ville, Lincoln Continental, and Jaguar XJ. The W126 was known for its engineering robustness and sophisticated design.

Features:

Comprehensive coverage, vehicle-specific data, dealership-level accuracy, step-by-step instructions, diagrams, illustrations, wiring schematics, and specifications. Digital format allows for easy printing and portability.

📋 Manual Details

Coverage:

All models and all repairs A-Z for the 1985 Mercedes-Benz W126 SEL

Page Count:

Not specified, but described as comprehensive and containing everything needed.

Manual Type:

Factory Service and Repair Manual

Language:

English

Format:

PDF (Digital)

📖 Manual Coverage

Maintenance:

Scheduled maintenance, routine inspections, fluid checks and changes.

Engine:

Engine mechanical, internal components, seals, gaskets, timing, cylinder head, block assembly.

Control System:

Engine control unit (ECU) diagnostics, sensors, actuators, fuel injection systems.

Mechanical:

General mechanical systems, component removal and installation.

Fuel Service Specifications:

Fuel delivery, injectors, fuel pump, pressure regulator, specifications and testing.

Emission Control:

Emission control systems, catalytic converter, EGR, evaporative emission control.

Intake Exhaust Cooling:

Intake manifold, exhaust system, cooling system, radiator, water pump, thermostat, fan.

Lube:

Lubrication system, oil pump, oil filter, oil cooler, lubrication points and specifications.

Ignition Starting Charging:

Ignition system (distributor, coil, spark plugs), starting system (starter motor, solenoid), charging system (alternator, battery).

Auto Transmission Clutch:

Automatic transmission overhaul, repair, fluid specifications, valve body, torque converter.

Manual Transmission:

Manual transmission (if applicable to the W126 SEL in 1985 - typically automatic for SEL) overhaul, repair, clutch service.

Transfer Propeller Shaft:

Drive shafts, universal joints, U-joints, propeller shaft balancing.

Drive Shaft:

Drive shafts, U-joints, balancing, installation.

Differential:

Rear axle differential service, fluid specifications, overhaul.

Axle Suspension:

Front and rear suspension components, control arms, ball joints, bushings, shock absorbers, springs, self-leveling suspension (if equipped).

Tire Wheel:

Wheel alignment, tire balancing, lug nut torque specifications.

Brake Control:

Brake system hydraulics, master cylinder, brake fluid specifications, ABS (if equipped).

Brake:

Brake pads, rotors, calipers, lines, bleeding procedure, parking brake mechanism.

Parking Brake:

Parking brake system maintenance and adjustment.

Steering Column:

Steering column components, tilt and telescoping mechanisms, ignition lock cylinder.

Power Steering:

Power steering pump, hoses, steering gear, fluid specifications, bleeding.

Air Condition:

Air conditioning system service, refrigerant, compressor, evaporator, condenser, climate control unit.

Suppl Restraint System:

Supplemental Restraint System (SRS) - Airbag system (if equipped for 1985, less common but possible), seat belt pre-tensioners.

Seat Belt:

Seat belt systems, pre-tensioners, inertia reels, maintenance.

Engine Immobilizer:

Engine immobilizer system (if equipped for the model year).

Cruise Control:

Cruise control system operation, diagnostics, and repair.

Wiper Washer:

Wiper motor, linkage, blades, washer fluid reservoir, pump, nozzles.

Door Lock:

Door lock mechanisms, central locking system, power locks, vacuum locks (common on Mercedes of this era).

Meter Audio Visual:

Instrument cluster, gauges, warning lights, audio system service and integration.

Horn:

Horn system operation and troubleshooting.

Windshield Glass Mirror:

Windshield replacement, power mirror adjustments and repair.

Instrument Panel:

Instrument panel removal and installation, gauge cluster repair.

Seat:

Seat adjustment mechanisms, power seat controls, seat upholstery.

Engine Hood Door:

Hood latch and hinges, door hinges, latches, and seals.

Exterior Interior:

Body panels, trim, bumpers, interior trim panels, headliner.

Electrical:

General electrical system troubleshooting, wiring harnesses, fuses, relays, lighting.

Multiplex Can Communication:

Multiplex wiring systems and CAN communication (early forms if applicable, more likely simple multiplexing for this era) diagnostics.

Procedures:

Complete step-by-step instructions for diagnosis, maintenance, service, and repair.

Depth:

Vehicle-specific and dealership-level technical accuracy, covering all repairs A-Z.

📊 Manual Specifications

File Format:

PDF

Print Quality:

High-quality, factory data with clear illustrations and schematics. Printable for enlarged viewing of diagrams.

Binding Type:

N/A (Digital PDF, printable pages).

Paper Type:

N/A (Digital PDF, user chooses paper type for printing).

⚙️ Engine Specifications

Engine Code:

Likely M117 (V8) engine for the SEL model. Specific displacement would depend on the exact variant (e.g., 5.0L).

Horsepower Torque:

For the 1985 5.0L M117 V8, expect approximately 180-200 horsepower and around 250-270 lb-ft of torque (figures varied slightly by market and emission controls).

Fuel Injection:

Bosch K-Jetronic (CIS - Continuous Injection System) or potentially early KE-Jetronic (CIS-E - Electronic Control) for the 1985 model year, coupled with mechanical fuel distribution.

🔧 Transmission

Transmission Type:

4-speed automatic transmission (e.g., 4G-Tronic).

Optional Transmission:

Manual transmission was not typically offered on the W126 SEL.

Transmission Features:

Electronically controlled shift points (on KE-Jetronic models), torque converter lock-up, sport/economy modes (depending on specific system).

📐 Dimensions

Wheelbase:

Approximately 116.9 inches (2970 mm) for the SEL long-wheelbase variant.

Curb Weight:

Around 4,000 - 4,300 lbs (1814 - 1950 kg), depending on engine and options.

🛡️ Safety Features

Safety Ratings:

While formal crash test ratings as we know them today were less prevalent, the W126 was renowned for its robust body structure, crumple zones, and passive safety features, contributing to excellent occupant protection for its era.

Active Safety:

Four-wheel disc brakes, Anti-lock Braking System (ABS) often optional or standard on higher trims, power steering.

Passive Safety:

Reinforced body structure, energy-absorbing steering column, safety glass, front and rear crumple zones, seat belts, potentially early airbag systems on later 1985 models or as an option.

💡 Technology Features

Infotainment System:

Original infotainment likely consisted of an analog radio receiver with cassette player, possibly with early graphic equalizers and multi-speaker systems. Manual covers basic diagnostics and speaker replacement.

Driver Assistance:

Features like cruise control were advanced for the time. ABS was a significant driver assistance technology available.

Connectivity:

No modern connectivity features such as Bluetooth or USB. Basic power antennas for radio reception.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or 6-12 months, depending on driving conditions and oil type used. Manual will provide specific recommendations.

Engine Oil Type:

API SG or SH specification, SAE 10W-30 or 10W-40 for many climates. Specific viscosity may vary with temperature. Manual will specify.

Transmission Fluid:

MB 236.1 or MB 236.3 specification automatic transmission fluid (ATF) for 4-speed transmissions.

Coolant Type:

Ethylene glycol-based antifreeze, typically a 50/50 mix with distilled water. Mercedes-specific coolant may be recommended.

Brake Fluid:

DOT 3 or DOT 4 brake fluid.

Common Problems:

Vacuum-operated central locking and climate control issues, deteriorating rubber hoses and seals, potential head gasket leaks, fuel distributor seal leaks (K-Jetronic), SRS warning light activation (if equipped), rust in common areas (wheel arches, rocker panels).

📚 Vehicle History

Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, safety, and luxury, dating back to the early automotive pioneers. The W126 continued this legacy, building upon previous S-Class generations.

Evolution:

The W126 S-Class, introduced in 1979, was a significant evolution from the W116. The SEL designation signifies the long-wheelbase variant. The 1985 model year represents a mid-cycle update or continuation of a well-established platform.

Production Years:

The W126 platform was produced from 1979 to 1991. The 1985 model falls within the first series of production.

🏆 Awards & Recognition

Recognitions:

The W126 S-Class was consistently lauded by automotive journalists and critics for its comfort, build quality, and engineering prowess, often cited as the benchmark luxury sedan of its era. While specific 'awards' might not be documented in the same way as modern vehicles, its market reception and critical acclaim were significant.