Years Covered:
1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Body Styles Covered:
Sedan (W123), Estate/Station Wagon (S123), Coupe (C123), Long Wheelbase Sedan (V123)
Target Audience:
Owners of Mercedes-Benz W123 280E models seeking to perform their own maintenance and repairs, as well as independent repair shops.
Source Authenticity:
Official factory service manual, providing accurate and authorized repair information, distinguishing it from unofficial or third-party guides.
Content Detail:
Hundreds of pages of detailed instructions, illustrations, diagrams, and specifications, mimicking the knowledge of factory-trained technicians.
Usability:
User-friendly interface, enabling easy navigation and printing of specific sections or the entire manual.
Cost Savings:
Enables owners to save significantly on labor costs by performing their own servicing.
Engine Service:
Complete engine overhaul, diagnosis, repair, and tuning for the M110 2.8L inline-six engine.
Fuel System:
Fuel injection system (Bosch K-Jetronic), fuel pump, lines, filter, injectors, and fuel tank service.
Ignition System:
Ignition system components, timing, troubleshooting, and repair.
Transmission Service:
Manual and automatic transmission overhaul, repair, fluid changes, and troubleshooting.
Drivetrain:
Differential, axles, driveshaft, universal joints, and rear axle service.
Brakes:
Hydraulic brake system, calipers, master cylinder, brake lines, rotors, pads, and parking brake service.
Suspension:
Front and rear suspension components, shock absorbers, springs, control arms, bushings, and alignment.
Steering:
Power steering system, steering box, linkages, and troubleshooting.
Cooling System:
Radiator, water pump, thermostat, hoses, fan, and coolant service.
Electrical System:
Full coverage of all electrical components, wiring diagrams, lighting, charging system (alternator/generator), starting system (starter), and battery service.
Climate Control:
Heater core, ventilation system, air conditioning system (if equipped), and related components.
Chassis Body:
Body structure, doors, hood, trunk, fenders, bumpers, glass, and related hardware.
Interior:
Seats, dashboard, trim panels, headliner, and related interior components.
Emission Control:
Emission control systems, catalytic converter (if applicable), and related components.
Restraint System:
Seat belts and other passive safety restraint systems.
Maintenance:
Routine maintenance, fluid checks and changes, filter replacements, belt adjustments, and general servicing.
Troubleshooting:
Comprehensive diagnostic procedures and troubleshooting guides for common and uncommon issues.
Repair:
Step-by-step repair instructions for all major and minor components and systems.
Rebuilding:
Detailed procedures for rebuilding major components such as engines and transmissions.
Diagnostics:
Advanced diagnostic techniques for identifying and resolving mechanical and electrical faults.
Wiring Diagrams:
Complete and detailed electrical wiring diagrams for all vehicle systems.
Depth:
Factory-level technical information, suitable for professional technicians and experienced DIY mechanics. Covers everything from basic adjustments to complete overhauls.
Engine Type:
2.8 Liter (2746 cc) SOHC Inline-Six Cylinder
Bore X Stroke:
86.0 mm x 79.0 mm
Horsepower Est:
182-185 hp @ 5800-6000 rpm (Varies slightly by year and market)
Torque Est:
222-228 lb-ft @ 3500-4500 rpm (Varies slightly by year and market)
Fuel Delivery:
Bosch K-Jetronic Mechanical Fuel Injection
Recommended Fuel:
Unleaded gasoline (87+ octane)
Coolant Type:
Ethylene glycol-based coolant (typically 50/50 mix with distilled water)
Engine Oil Capacity:
Approximately 6.5 - 7.0 liters (6.9 - 7.4 US quarts) with filter change.
Engine Oil Specification:
Refer to manual for specific viscosity grades (e.g., 20W-50, 15W-40) based on ambient temperature. API service classification SG or equivalent recommended.
Transmission Type:
4-speed Manual Transmission (common in early models)
Transmission Type:
4-speed Automatic Transmission (e.g., 4G-TRONIC 722.1/722.3, often optional)
Automatic Features:
Torque converter, hydraulic control. Specific shift points and modes can be adjusted.
Automatic Transmission Fluid:
MB Specification 236.1 (e.g., Dexron II or equivalent). Capacity approx. 7-8 liters.
Manual Transmission Fluid:
API GL-4 or GL-5 gear oil, viscosity typically 75W-90 or 80W-90. Capacity approx. 1.5-2.0 liters.
Oil Change Interval:
Typically every 10,000-15,000 km (6,000-9,000 miles) or 12 months, whichever comes first, depending on driving conditions and oil used. Consult manual for exact recommendations.
Transmission Fluid Change:
Automatic: ~50,000 km (30,000 miles). Manual: Inspect and change as needed, typically every 80,000-100,000 km (50,000-60,000 miles).
Brake Fluid Change:
Every 2 years, regardless of mileage, to prevent moisture absorption and corrosion.
Coolant Change:
Typically every 2-3 years or 40,000-50,000 km (25,000-30,000 miles).
Power Steering Fluid:
MB Specification 236.3 (e.g., Dexron II or ATF compatible with power steering systems).
Brake Fluid:
DOT 3 or DOT 4.
Common Faults:
Cracked dashboard (sun exposure), vacuum leak issues affecting central locking and climate control, rust (particularly around wheel wells, door bottoms, and sunroofs), fuel distributor leaks (K-Jetronic), worn suspension bushings.
Diesel Specific Note:
This manual is for the 280E gasoline model; diesel variants (e.g., 240D, 300D) have different engine and fuel system maintenance requirements.
Mercedes Benz Legacy:
Represents Mercedes-Benz's commitment to engineering excellence, durability, and safety established in the mid-20th century.
W123 Series Introduction:
The W123 series, introduced in 1975, succeeded the W114/W115 range and was produced until 1986. It was renowned for its build quality and longevity.
280E Positioning:
The 280E was positioned as a more powerful, refined, and luxurious variant within the W123 lineup, often considered a 'baby S-Class'.
Production Period:
The W123 series was produced from 1975 to 1986. The 280E model specifically covered by this manual spans 1976-1985.
Manufacturing Locations:
Primarily Germany, with some assembly also occurring in other international locations.
