🏷️ Basic Information Identification Make: Mercedes-Benz Model: W123 Series Codes Chassis Code: W123 👋 Introduction Market Position Segment Placement: Executive Mid-size Sedan/Estate/Coupe/Limousine. Known for exceptional build quality, durability, and engineering. Competitive Analysis Key Competitors: BMW 5 Series (E28), Audi 100, Volvo 240/740, Ford Granada, Saab 900. Key Features Vehicle Attributes: Robust construction, legendary longevity, comfortable ride, excellent safety for its era, a wide range of efficient diesel and powerful petrol engines. 📋 Manual Details Coverage Areas Primary Coverage: Comprehensive Service and Repair Page Count Estimated Pages: 800+ Manual Type Type: Factory Service Manual / Workshop Manual Content Type: Technical Service Manual, Workshop Manual, Repair Manual. Language Language: English Format Format: Digital (PDF) 📖 Manual Coverage Systems Covered Engine Systems: Engine mechanical, fuel injection (Bosch inline, K-Jetronic, M-Jetronic), diesel injection, cooling system, lubrication system, ignition system (petrol), starting system, charging system, emission control systems. Transmission Drivetrain: Manual transmissions (4-speed, 5-speed), Automatic transmissions (3-speed, 4-speed), clutch system, driveshafts, differentials, rear axle assembly. Suspension Steering: Front suspension (independent, MacPherson struts, coil springs, wishbones), Rear suspension (independent, semi-trailing arms, coil springs), shock absorbers, steering system (power steering, steering box), wheel alignment. Brakes: Front disc brakes, rear drum brakes (and disc on some models), brake system hydraulics, brake booster, parking brake system, ABS (on later models). Electrical Electronics: Wiring diagrams, lighting systems, instrumentation, switches, relays, fuses, starter motor, alternator, battery, power windows, central locking, climate control system wiring. Body Chassis: Body shell construction, doors, hood, trunk lid, bumpers, glass, interior trim, seats, body sealing, rust prevention, chassis components. Climate Control: Manual and automatic climate control systems, including heater core, evaporator, blower motor, A/C compressor, refrigerant charging, and vacuum control for flaps. Procedures Included Maintenance Procedures: Oil changes, filter replacements, coolant checks/flushes, brake fluid changes, spark plug replacement, air filter replacement, fuel filter replacement, belt inspections/replacement, battery maintenance, lubrication points. Repair Procedures: Engine overhaul, cylinder head removal/installation, transmission removal/installation, clutch replacement, brake caliper/master cylinder replacement, suspension component replacement, steering box overhaul, starter/alternator replacement, fuel injector servicing, diesel injection pump servicing. Troubleshooting: Diagnosis of engine performance issues, electrical faults, braking problems, starting issues, transmission shifting problems, HVAC system malfunctions, fuel system issues. Diagnostics: Diagnostic procedures for fuel injection systems (K-Jetronic, Diesel), ignition timing, electrical circuits, and common mechanical faults. Technical Depth Depth Of Information: Comprehensive. Includes detailed step-by-step repair instructions, specifications, torque values, diagnostic flowcharts, and exploded views. 📊 Manual Specifications File Format Digital Format Details: Searchable PDF with bookmark navigation for easy chapter access. High-resolution scans of original documentation. Print Quality Scanned Quality: Excellent clarity and readability, preserving original diagrams and text. Binding Type Digital Binding: N/A (Digital File) Paper Type Digital Paper Type: N/A (Digital File) Completeness Manual Completeness: A complete factory-level workshop manual covering all aspects of maintenance, repair, and diagnostics for the W123 series. ⚙️ Engine Specifications Primary Engine Engine Families: M115, M116, M117 (Petrol Inline-4, V8), OM615, OM616, OM617 (Diesel Inline-4, Inline-5). Performance Representative Petrol Performance: 2.3L (M102) Inline-4: Approx. 105-130 hp. 2.8L (M110) Inline-6: Approx. 140-185 hp. 3.8L (M116) V8: Approx. 155-200 hp. Representative Diesel Performance: 2.4L (OM615) Diesel: Approx. 60-70 hp. 2.4L (OM616) Diesel: Approx. 70-80 hp. 3.0L (OM617) Turbo-Diesel: Approx. 88-125 hp. Fuel System Petrol Injection Systems: Stromberg carburetors (early models), Bosch K-Jetronic (mechanical fuel injection), Bosch M-Jetronic (early electronic fuel injection). Diesel Injection Systems: Bosch inline injection pumps, Bosch VE rotary injection pumps (turbo diesel). Engine Codes Explained Engine Code Breakdown: M = Petrol Engine, OM = Oelmotor (Oil Engine/Diesel), first digit indicates cylinder count (e.g., 6 for inline-6, 1 for inline-4/5), subsequent digits denote series/design. Example: OM617 = Diesel, 5 cylinders, 17 series. 🔧 Transmission Standard Standard Transmission: 4-speed manual transmission. Optional Optional Transmission: 5-speed manual transmission, 3-speed automatic transmission (e.g., 3HP20), 4-speed automatic transmission (e.g., 722.3, 722.4). Features Automatic Features: Lock-up torque converter on some later 4-speed automatics for improved fuel economy. 📐 Dimensions Exterior Sedan Length: Approx. 4725-4800 mm (186.0-189.0 in) Estate Length: Approx. 4765-4850 mm (187.6-190.9 in) Wheelbase: Approx. 2795-2810 mm (110.0-110.6 in) Coupe Length: Approx. 4710-4730 mm (185.4-186.2 in) Weights Curb Weight Range: Approx. 1350-1650 kg (2976-3638 lbs) depending on body style and engine. 🛡️ Safety Features Ratings Era Specific Safety: Considered exceptionally safe for its time. Strong passenger cell, padded dashboard, energy-absorbing steering column, laminated windshield. Later models offered optional airbags and ABS. Active Features Active Safety Features: Power assisted brakes, optional ABS (Anti-lock Braking System) on some later models. Passive Features Passive Safety Features: Reinforced passenger cell, crumple zones, driver's side airbag (optional), padded interior, seat belts. 💡 Technology Features Infotainment Infotainment Features: Basic analogue radio, cassette player (optional). Focus was on mechanical reliability and driver comfort over advanced electronics. Driver Assistance Driver Assistance Systems: Limited by era. Power steering, cruise control (optional on some models), ABS (optional on later models). Connectivity Connectivity Features: None in the modern sense. Analog radio...