🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W123 280S

Model Generation:

First Generation W123

Production Start Year:

1976

Production End Year:

1985

Chassis Code:

W123

👋 Introduction

Target Audience:

Do-it-yourself enthusiasts and experienced automotive technicians for the Mercedes-Benz W123 280S.

Advantage:

Digital format offers cost savings and convenience over traditional paper manuals; comprehensive coverage for all aspects of repair and maintenance.

Features:

Official full factory service repair manual, hundreds of pages, detailed step-by-step instructions, hundreds of photos and illustrations, printable, no expiry dates.

📋 Manual Details

Primary Coverage:

Mercedes-Benz W123 280S

Covered Years:

1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985

Estimated Pages:

Hundreds

Type:

Factory Service Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Engine Service Repair:

Yes

Transmission Service Repair:

Yes

Brake System:

Yes

Wiring Diagrams:

Yes

Electrical System:

Yes

Suspension:

Yes

Steering:

Yes

Cooling System:

Yes

Fuel Injection:

Yes

Fuel System:

Yes

Emission System:

Yes

Heating Air Conditioning:

Yes

Engine Control System:

Yes

Chassis Body:

Yes

Restraint System:

Yes

Interior:

Yes

Differential Drive:

Yes

Axle:

Yes

General Maintenance:

Yes

Troubleshooting:

Yes

Periodic Lubrication:

Yes

Complete Disassembly Reassembly:

Yes

Depth:

Comprehensive, step-by-step instructions with hundreds of photos and illustrations, suitable for DIYers and experienced mechanics.

📊 Manual Specifications

Digital Format:

PDF

Compatibility:

All versions of Windows and Mac

Access Method:

Downloadable, viewable on PCs, laptops, smartphones, tablets, and via web browser.

Printable:

Yes, individual pages or entire manual.

Binding:

Not applicable (digital format)

Paper Type:

Not applicable (digital format)

⚙️ Engine Specifications

Engine Type:

Inline-6 Cylinder, Naturally Aspirated

Engine Code Common:

M110 (early variants), M110.987 (later variants)

Displacement:

2.8 Liters (2778 cc)

Bore X Stroke:

86.0 mm x 80.0 mm

Compression Ratio:

8.0:1 or 8.7:1 (depending on market and year)

Horsepower Approximate:

138-154 hp @ 5000-5200 rpm (depending on market and emission controls)

Torque Approximate:

213-230 Nm @ 3000-3500 rpm (depending on market and emission controls)

Fuel Delivery:

Fuel Injection (Bosch K-Jetronic/CIS for most years)

Fuel Type:

Unleaded gasoline (Premium recommended)

Spark Plugs:

Champion N9Y or NGK BP5ES (typical, consult manual for specific part numbers)

Engine Oil Capacity:

Approximately 6.5 - 7.0 Liters (6.9 - 7.4 US Quarts) with filter change.

Engine Oil Specification:

API SG or higher, viscosity grade 20W-50 or 15W-40 recommended for general use, consult manual for specific temperature ranges.

🔧 Transmission

Type:

4-Speed Manual (typical for base models)

Type:

4-Speed Automatic (optional, e.g., 4G-TRONIC)

Automatic Features:

Torque converter, selective gear programs (e.g., Economy/Performance).

Manual Transmission Fluid Type:

API GL-4 SAE 80W-90 (typical, verify with manual)

Automatic Transmission Fluid Type:

MB-Approval 236.1 (e.g., Dexron-II compatible, verify with manual)

📐 Dimensions

Body Styles:

Sedan (4-door), Coupe (2-door), Wagon (T-model, 5-door, introduced later)

Wheelbase:

Approx. 2795 mm (110.0 inches)

Length:

Approx. 4735 mm (Sedan) / 4770 mm (Coupe) / 4765 mm (Wagon)

Width:

Approx. 1790 mm

Height:

Approx. 1430 mm (Sedan/Coupe) / 1500 mm (Wagon)

Curb Weight Approximate:

1400 - 1550 kg (depending on body style and equipment)

Gross Vehicle Weight Rating Gvwr:

Varies by model, consult manual.

Wheel Bolt Pattern:

5x112

Typical Tire Sizes:

175 HR 14, 195/70 R14, 185 HR 14 (depending on model and year)

🛡️ Safety Features

Historical Safety Focus:

Known for robust build quality and passenger safety features for its era.

Brakes:

Front: Ventilated Disc Brakes; Rear: Drum Brakes (standard). ABS not typically available on early models.

Seatbelts:

Standard front seatbelts, optional rear seatbelts and pre-tensioners.

Body Structure:

Reinforced safety cell, crumple zones.

💡 Technology Features

Audio System:

Typically an AM/FM radio with cassette player, often with upgraded aftermarket units available.

Features:

Power steering, power windows (optional), central locking (vacuum operated), cruise control (optional).

Features:

Limited by era; primarily analog systems. Modern integrations typically aftermarket.

🔧 Maintenance

Oil Change Interval:

Typically every 7,500 to 10,000 miles (12,000 to 16,000 km) or annually, whichever comes first. Consult manual for specific conditions.

Tune Up Interval:

Spark plugs, filters, and ignition system checks at intervals recommended by the manual, often around 15,000-30,000 miles.

Transmission Service:

Automatic transmission fluid and filter change typically every 30,000 to 50,000 miles. Manual transmission fluid change less frequent, around 60,000 miles.

Coolant:

50/50 mixture of Mercedes-Benz approved antifreeze and distilled water.

Brake Fluid:

DOT 3 or DOT 4 brake fluid (verify with manual).

Common Problems:

Rust (particularly in wheel arches, door bottoms, and undercarriage), vacuum line failures affecting central locking and other systems, climate control flap actuators, differential seal leaks, and occasional injector issues on fuel-injected models.

📚 Vehicle History

Brand Legacy:

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

W123 Significance:

The W123 generation is celebrated for its exceptional build quality, reliability, and comfortable ride, often referred to as the 'ultimate driving machine' of its time. It followed the W114/W115 generation.

Manufacturing Locations:

Primarily West Germany.

Production Numbers:

Over 2.7 million units produced across all body styles, making it one of Mercedes-Benz's most successful models.

🏆 Awards & Recognition

Industry Acclaim:

Consistently recognized by automotive journalists and enthusiasts as one of the most reliable and well-built Mercedes-Benz models.