🏷️ Basic Information

Make:

Mercedes-Benz

Model:

560 SEC

Chassis Code:

C126

Model Years Covered:

1985-1991

Engine Code Primary:

M117 (V8 SOHC)

Engine Code Details:

M117.960, M117.967

👋 Introduction

Positioning:

The Mercedes-Benz 560 SEC (C126) was a flagship luxury grand tourer, representing the pinnacle of automotive engineering and comfort in its era. It appealed to discerning buyers seeking performance, prestige, and sophisticated design.

Competitors:

Competed with other high-end European coupes like the BMW 8 Series (later models), Jaguar XJ-S, and Porsche 928.

Model Attributes:

Powerful V8 engine, luxurious interior appointments, advanced (for its time) suspension and safety features, elegant coupe styling, and exceptional build quality.

User Benefit:

Empowers owners and independent mechanics to confidently perform maintenance, repairs, and diagnostics, saving costs and preserving the vehicle's originality and value.

📋 Manual Details

Primary Coverage:

Comprehensive service, repair, maintenance, and troubleshooting for Mercedes-Benz 560 SEC (C126) models from 1985 to 1991.

Specific Topics:

Engine mechanical, fuel system, ignition system, cooling system, exhaust system, transmission (automatic and manual), driveshaft, suspension, steering, brakes, electrical system, climate control, bodywork, interior, and more.

Years Covered Detail:

Specifically covers 1985, 1986, 1987, 1988, 1989, 1990, and 1991 model years of the Mercedes-Benz 560 SEC.

Estimated Page Count:

Over 1000 pages (estimated across all covered manuals).

Type:

Service and Repair Manual

Language:

English

Delivery Format:

Digital Download (PDF/WINRAR)

📖 Manual Coverage

Engine Mechanical:

Detailed procedures for inspection, disassembly, overhaul, and reassembly of the M117 V8 engine, including cylinder heads, pistons, crankshaft, camshafts, timing components, lubrication system, and cooling system.

Fuel System:

Comprehensive coverage of the Bosch KE-Jetronic fuel injection system, including fuel pump, fuel filter, fuel accumulator, cold start enrichment, injectors, air flow meter, and control pressure regulator.

Ignition System:

Diagnosis and repair of the electronic ignition system, including coil, distributor, ignition control module, and spark plug troubleshooting.

Transmission:

Service and repair procedures for the 4-speed automatic transmission (722.3 or 722.4), including fluid and filter changes, adjustment procedures, and common troubleshooting steps.

Suspension Steering:

Detailed instructions for front and rear suspension components, including shock absorbers, struts, control arms, ball joints, tie rods, steering gearbox, and power steering system. Includes coverage for optional systems like ADS (Active Damping System), ASD (Automatic Slip Differential), and 4MATIC all-wheel drive.

Brakes:

Complete brake system service, including disc brake inspection and replacement, brake fluid flushing and replacement, parking brake adjustment, and troubleshooting of hydraulic and mechanical components.

Electrical System:

Extensive wiring diagrams, fuse box locations, component testing, and troubleshooting for all electrical systems, including lighting, instrumentation, power accessories, and engine control unit (ECU).

Climate Control:

Service and repair for the automatic climate control system, including refrigerant charge checks, filter replacement, and component diagnosis.

Body Interior:

Procedures for inspecting body structure, water leakage, corrosion, door mechanisms, hinges, sunroof operation, soft top maintenance, and seatbelt inspection.

Emissions Control:

Information on emission control systems, including oxygen sensors and catalytic converters, and related troubleshooting.

Routine Maintenance:

Oil and filter changes, fluid level checks and top-offs (engine oil, coolant, brake fluid, power steering fluid, transmission fluid, differential fluid, windshield washer fluid), air filter replacement, spark plug replacement, V-belt inspection and replacement, tire pressure correction, and general lubrication.

Engine Repair:

Valve clearance adjustment, injection timing adjustment, idle speed adjustment, fuel filter replacement, intake and exhaust manifold seating inspection, oxygen sensor replacement, and engine mount retorquing.

Transmission Repair:

Automatic transmission fluid and filter change, checking and correcting fluid levels, and manual transmission oil change and level checks.

Suspension Steering Repair:

Ball joint inspection, front and rear axle oil changes and level checks, steering play checks, and tightening of steering bolts.

Brake Repair:

Brake fluid replacement, brake pad and disc thickness inspection, parking brake adjustment, and brake line inspection.

Electrical Diagnostics:

Troubleshooting of warning lamps, checking battery fluid levels, cleaning drain channels, and inspection of exterior and interior lighting.

Bodywork Maintenance:

Lubrication of door hinges and locks, sunroof rail cleaning and greasing, soft top checking, windshield wiper replacement, and paint damage inspection.

Troubleshooting Guides:

Comprehensive troubleshooting flowcharts and symptom-based diagnostic guides for common problems.

Depth:

Extremely high. Covers everything from basic preventative maintenance to complete engine rebuilds, complex electrical diagnostics, and detailed troubleshooting of all major vehicle systems. Provides step-by-step instructions with diagrams and illustrations.

Diagnostic Procedures:

Detailed diagnostic procedures for all major systems, including identifying fault codes (where applicable), checking sensor outputs, and troubleshooting intermittent issues.

📊 Manual Specifications

Primary Format:

PDF / WINRAR

Compatibility:

Win95/98/ME/XP/vista/7/8/Linux/MAC, IOS, Android devices.

Searchability:

Likely searchable text within PDFs, allowing for quick information retrieval.

Content Type:

Collection of service manuals for each model year, providing year-specific data.

Quality:

High resolution diagrams and illustrations for clarity.

Digital Format:

Downloadable files (not a physical book).

Not Applicable:

N/A (Digital)

⚙️ Engine Specifications

Engine Type:

Naturally Aspirated V8

Displacement:

5.5 Liters (5549 cc)

Bore X Stroke:

94.5 mm x 98.5 mm

Compression Ratio:

8.8:1

Valvetrain:

SOHC (Single Overhead Camshaft) with 2 valves per cylinder

Horsepower Peak:

Approx. 238-255 hp (depending on market and year)

Torque Peak:

Approx. 300-320 lb-ft (depending on market and year)

Injection System:

Bosch KE-Jetronic Electronic Fuel Injection

Fuel Type:

Unleaded Gasoline (Premium)

Cooling Medium:

Water-cooled

Oil Capacity:

Approx. 8.5 Liters (8.9 US Quarts) with filter

Recommended Oil Viscosity:

SAE 10W-40 or 15W-40 (refer to manual for specific climate conditions)

🔧 Transmission

Type:

4-speed Automatic Transmission (722.3 or 722.4)

Type:

None offered for 560 SEC models in this period.

Transmission Fluid Type:

MB 236.1 or MB 236.2 Automatic Transmission Fluid (ATF) or equivalent.

Transmission Fluid Capacity:

Approx. 2.5 Liters (2.6 US Quarts) for torque converter drain and fill (total capacity higher).

📐 Dimensions

Length:

Approx. 5004 mm (197.0 in)

Width:

Approx. 1798 mm (70.8 in)

Height:

Approx. 1398 mm (55.0 in)

Wheelbase:

Approx. 2800 mm (110.2 in)

Curb Weight:

Approx. 1700-1800 kg (3748-3968 lbs)

Gross Vehicle Weight Rating:

Approx. 2250 kg (4960 lbs)

🛡️ Safety Features

Crash Testing:

While official modern crash test ratings are not directly applicable to vehicles of this era, Mercedes-Benz vehicles were renowned for their robust construction and passive safety features.

Optional Systems:

Optional ABS (Anti-lock Braking System), ASD (Automatic Slip Differential), and ADS (Active Damping System) contributed to active safety.

Structural Design:

Reinforced passenger cell, crumple zones, and strong pillar construction.

Restraints:

Front seat belts, optional driver's side airbag (later models).

💡 Technology Features

Audio System:

Typically featured high-quality Becker audio systems, often with cassette players and premium speaker configurations.

Navigation:

Not available in the modern sense; optional early navigation systems may have been present on very late models in some markets.

ABS:

Optional Anti-lock Braking System (ABS) was a significant technological feature for its time.

Traction Control:

Optional ASD (Automatic Slip Differential) provided traction control capabilities.

Climate Control:

Automatic climate control system for precise temperature management.

Suspension:

Optional ADS (Active Damping System) allowed for adjustable ride comfort.

Connectivity Features:

Limited to basic features such as power windows, power seats, central locking, and cruise control. No modern infotainment or Bluetooth connectivity.

🔧 Maintenance

Oil Change Interval:

Approximately every 7,500 to 10,000 miles or 12 months, whichever comes first (refer to original owner's manual for precise intervals and conditions).

Transmission Fluid Change Interval:

Approximately every 30,000 to 50,000 miles (highly recommended for longevity).

Coolant Change Interval:

Approximately every 2-3 years or 30,000 miles.

Coolant Type:

Mercedes-Benz approved antifreeze/coolant concentrate (e.g., G05 or equivalent) mixed with distilled water. Refer to manual for specific part numbers and ratios.

Brake Fluid Type:

DOT 3 or DOT 4.

Power Steering Fluid Type:

Mercedes-Benz Power Steering Fluid (e.g., G000 000 000 137) or Dexron III/Mercon equivalent.

Common Problems:

Wiring harness degradation (especially insulation), fuel distributor leaks, vacuum hose deterioration, SRS (Supplemental Restraint System) warning lights, climate control actuator failures, and potential rust in common areas (wheel arches, door bottoms).

Maintenance Focus:

Proactive maintenance of the fuel injection system, electrical connectors, and cooling system is crucial for reliability.

📚 Vehicle History

Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, safety, and durability, dating back to the invention of the automobile.

C126 Generation:

The C126 coupe was the successor to the C107 coupe, based on the W126 S-Class sedan platform. The 560 SEC represented the top-tier performance and luxury offering in the C126 range.

Manufacturing Location:

Germany

Production Years:

C126 coupes produced from 1981 to 1991. The 560 SEC variant was introduced in 1985.

🏆 Awards & Recognition

General Reputation:

Consistently lauded for its build quality, luxury, performance, and timeless design. Often considered a 'modern classic' and a desirable collector's item.

Collectible Status:

Highly regarded in the classic and collectible car market.