Positioning:
The Mercedes-Benz W123 is renowned for its robust engineering, build quality, and durability, making it a highly sought-after classic vehicle. This manual caters to owners and technicians aiming to maintain or restore these iconic automobiles.
Competitors:
Competed against other premium sedans and coupes of its era, such as BMW 5 Series, Audi 100, and Volvo 240/740 series, but distinguished itself with superior build quality and luxury appointments.
Vehicle Appeal:
Known for exceptional reliability, comfortable ride, and understated luxury, making it a popular choice for daily driving and long-distance travel. Offers a classic driving experience with robust mechanicals.
Value:
Provides comprehensive, manufacturer-level repair and maintenance information, empowering owners to perform tasks themselves, thereby saving on dealership labor costs and ensuring proper upkeep of a classic vehicle.
Primary Coverage:
Full Workshop Service and Repair
Secondary Coverage:
Maintenance, Troubleshooting, Diagnostics, Overhaul Procedures, Wiring Diagrams
Estimated Page Count:
Hundreds (typical for comprehensive workshop manuals)
Type:
Workshop Service Manual, Repair Manual, Factory Service Manual
Delivery Method:
Instant Download
Engine:
Engine mechanicals, fuel system, ignition system, lubrication, cooling system, emission controls
Transmission:
Manual and automatic transmission overhaul, operation, and repair
Drivetrain:
Driveshafts, differentials, axles
Suspension:
Front and rear suspension, steering components, shock absorbers, springs
Brakes:
Brake system components (discs, calipers, drums, master cylinder), hydraulic system, parking brake
Electrical:
Battery, charging system, starting system, lighting, ignition, instrumentation, wiring diagrams
Bodywork:
Body panel removal and installation, interior trim, glass, doors, locks, hinges
HVAC:
Heating, ventilation, and air conditioning (if equipped)
Chassis:
Frame, subframes, body mounts
Maintenance:
Periodic maintenance charts, fluid changes, filter replacements, lubrication
Troubleshooting:
Diagnostic procedures for common and uncommon faults, symptom-based troubleshooting guides
Repair:
Step-by-step repair instructions for all major components and systems
Overhaul:
Complete engine and transmission rebuild procedures
Diagnostics:
Diagnostic fault codes, electrical system testing, mechanical component checks
Wiring Diagrams:
Comprehensive electrical schematics for all vehicle systems
Technical Specifications:
Torque specifications, clearances, alignment data, fluid capacities, engine specifications
Depth:
Suitable for professional technicians and advanced DIY mechanics, covering detailed diagnostics and complete rebuilds.
Engine Options Covered:
Likely covers a range of M115, M110, OM615, OM616, and OM617 diesel and gasoline engines as offered in the W123 series.
Typical Power Output Gasoline:
Ranges from approximately 75 hp (2.0L) to 180 hp (2.8L inline-6)
Typical Power Output Diesel:
Ranges from approximately 55 hp (2.0L diesel) to 80 hp (3.0L turbo-diesel)
Gasoline Engines:
Carbureted (e.g., Solex, Zenith) or Bosch K-Jetronic mechanical fuel injection
Diesel Engines:
Bosch inline injection pumps and glow plug systems
Engine Orientation:
Inline (4-cylinder, 5-cylinder diesel, 6-cylinder)
Cylinder Block Material:
Cast Iron
Cylinder Head Material:
Aluminum Alloy
Standard Transmission:
4-speed or 5-speed manual transmission
Optional Transmission:
3-speed or 4-speed automatic transmission (e.g., 3HP22, 4HP22)
Transmission Control:
Mechanical linkage for manual, hydraulic control for automatic
Automatic Transmission Fluid:
MB 236.2 or equivalent (e.g., Dexron II)
Manual Transmission Fluid:
GL-4 or GL-5 rated gear oil
Body Styles:
Sedan, Coupe, Estate (T-Model), Long Wheelbase Sedan
Wheelbase Sedan:
Approximately 2795 mm (110.0 in)
Wheelbase Coupe:
Approximately 2795 mm (110.0 in)
Wheelbase Estate:
Approximately 2820 mm (111.0 in)
Curb Weight Range:
Approximately 1300 kg to 1600 kg depending on body style and engine
Historical Safety Focus:
Known for strong passenger cell, safety-designed crumple zones, and robust construction, ahead of its time in safety features.
Active Safety:
Power-assisted steering, 4-wheel disc brakes (on most models), independent suspension
Passive Safety:
Reinforced A, B, and C pillars, safety glass, padded interior surfaces, seat belts
Oil Change Interval:
Typically 10,000-15,000 km or 6-12 months, depending on engine type and driving conditions
Filter Replacement:
Oil filter with every oil change, air filter and fuel filter at specified intervals (e.g., 20,000-40,000 km)
Spark Plug Replacement:
At intervals indicated by the manual, often every 30,000-50,000 km for gasoline engines
Engine Oil Specification:
API SG/SH or ACEA A2/A3 rated multi-viscosity oil, typically 10W-40 or 15W-40, check manual for specific viscosity based on climate.
Coolant Specification:
Ethylene glycol-based antifreeze mixed with distilled water (50/50 ratio). Mercedes-Benz specification 325.0 or 326.0.
Brake Fluid Specification:
DOT 3 or DOT 4 hydraulic brake fluid.
Common Wear Items:
Brake components, suspension bushings, exhaust system, fuel injectors (diesel), vacuum lines, head gasket (certain engines).
Diesel Specific Issues:
Glow plug issues, injection pump seals, carbon buildup in intake manifolds.
Gasoline Specific Issues:
Carburetor tuning, ignition system component wear, timing chain wear (M110).
Tire Pressure:
Refer to vehicle placard or manual for specific tire sizes and pressures (e.g., 30-35 PSI)
Wheel Bolt Pattern:
5x112 mm
Valve Adjustment:
Required for some gasoline engines (e.g., M110) at specific intervals.
Mercedes Benz Legacy:
Built on a legacy of engineering excellence and automotive innovation, synonymous with quality and luxury.
W123 Positioning:
Succeeded the W114/W115 series, representing a significant step forward in comfort, safety, and technology for its class.
Body Style Introduction:
Introduced as a sedan and coupe, with the popular T-Model (estate) version launched later, followed by a long-wheelbase sedan.
Production Period:
1976-1985
Production Volume:
Over 2.7 million units produced across all body styles, making it a very successful model for Mercedes-Benz.
Production Locations:
Primarily manufactured in Stuttgart, Germany, with some assembly in other international locations.
