🏷️ Basic Information Identification Make: Mercedes-Benz Model: W123 Series Model Variants Covered: 200D, 240D, 240TD, 300D, 300TD Codes Chassis Code: W123 Engine Codes Diesel: OM615, OM616, OM617 (various displacements) 👋 Introduction Market Position Segment: Mid-size executive sedan and wagon, known for durability, comfort, and reliability, particularly the diesel variants. Competitive Analysis Contemporaries: Competed with models from BMW (E21, E30), Audi (80/90), Volvo (240 Series), and other European luxury and durable sedans of the era. Key Features Durability: Renowned for its robust engineering and longevity, especially the diesel engines which often exceeded 500,000 miles. Comfort: Offered a comfortable ride and well-appointed interior, setting a standard for its class. Safety: Designed with a focus on safety, featuring crumple zones and a robust body structure. 📋 Manual Details Coverage Areas Vehicle Coverage: 1976-1985 Mercedes-Benz W123 Series (200D, 240D, 240TD, 300D, 300TD) Page Count Estimated Page Count: Approximately 1000+ pages (comprehensive workshop manual) Manual Type Type: Complete Workshop Service and Repair Manual Language Language: English Format Format: Digital (likely PDF, potentially printable) 📖 Manual Coverage Systems Covered Engine: Diesel engine overhaul, fuel injection system (Bosch VE rotary pump), cooling system, lubrication system, exhaust system, engine management (basic). Transmission: Manual transmission (4 & 5 speed) repair, automatic transmission (3 & 4 speed) overhaul and service, clutch system, drive shafts, differential. Brakes: Hydraulic brake system, front disc brakes (calipers, rotors), rear drum brakes, parking brake, brake fluid specifications, bleeding procedures. Suspension Steering: Front independent suspension (double wishbone), rear semi-independent suspension (swing axle/semi-trailing arm), shock absorbers, coil springs, steering box, power steering system. Electrical: 12V electrical system, battery, alternator, starter motor, ignition system (glow plug system for diesel), lighting system, wiring diagrams, fuses, relays, dashboard instruments. Body Chassis: Body construction, chassis components, doors, windows, sunroof, interior trim, seats, bumpers, corrosion protection. Procedures Included Maintenance: Scheduled maintenance, oil changes, filter replacements (oil, fuel, air), fluid level checks and top-ups, tune-up procedures. Repair Rebuild: Engine component replacement, transmission rebuild, brake system repair, suspension component overhaul, starter/alternator replacement. Diagnostics Troubleshooting: Systematic diagnostic flowcharts, common fault identification and correction for engine, transmission, electrical, and braking systems. Specifications Data: Torque specifications for all fasteners, engine clearances, timing specifications, fluid capacities, part numbers for common wear items. Technical Depth Depth: Comprehensive, covering from basic maintenance to complete engine and transmission rebuilds, including detailed diagnostic procedures. 📊 Manual Specifications File Format Digital Format: Likely PDF, optimized for digital viewing and printing. Print Quality Digital Quality: High resolution, clear diagrams and text for easy readability and reproduction. Binding Type Digital Binding: N/A (digital format) Paper Type Digital Paper Type: N/A (digital format) ⚙️ Engine Specifications Primary Engine Engine Type Diesel: Inline-four and inline-five cylinder naturally aspirated diesel engines. Engine Displacement 200D: 2.0 Liters (1988 cc) Engine Displacement 240D: 2.4 Liters (2399 cc) Engine Displacement 300D: 3.0 Liters (2998 cc) Engine Displacement 300Td: 3.0 Liters (2998 cc) - Turbocharged Diesel (for some markets/years, often associated with the OM617.95x engine). Performance Horsepower 200D: Approx. 55-60 hp Horsepower 240D: Approx. 65-70 hp Horsepower 300D: Approx. 77-80 hp Torque 300D: Approx. 130-140 lb-ft (176-190 Nm) Fuel System Injection System: Bosch inline mechanical fuel injection pump (VE rotary for later models). Fuel Type: Diesel fuel Engine Management Glow Plug System: Pre-glow system for cold starts, with manual or automatic timer controls. 🔧 Transmission Standard Standard Transmission: 4-speed manual transmission (common on base models). Optional Optional Transmission: 5-speed manual transmission, 3-speed automatic (722.1 series), 4-speed automatic (722.3 series). Features Automatic Transmission Features: Hydraulic torque converter, offering smooth power delivery and increasing fuel efficiency on the highway. 📐 Dimensions Exterior Body Styles: 4-door Sedan, 5-door Wagon (T-model). Wheelbase: Approximately 2790 mm (109.8 in) Weights Curb Weight: Varies by model, typically 1350-1550 kg (2976-3417 lbs) 🛡️ Safety Features Ratings Crash Test Information: While formal crash test ratings from modern bodies are not directly applicable, the W123 was engineered with advanced safety features for its era, including significant structural integrity and crumple zones. Active Features Braking System: Four-wheel disc brakes (front) and rear disc or drum brakes depending on model and market, with power assistance and dual-circuit hydraulics. Passive Features Body Structure: Reinforced passenger cell, crumple zones at front and rear, safety steering column. Interior Safety: Padded dashboard, energy-absorbing interior surfaces, safety belts (standard or optional depending on year/market). 💡 Technology Features Infotainment Radio System: Period-appropriate AM/FM radio, often with cassette player as an option. Driver Assistance Cruise Control: Optional cruise control system available on some models. Climate Control HVAC System: Manual heating and ventilation; optional (and often complex) air conditioning system. 🔧 Maintenance Service Intervals Oil Change Interval Diesel: Typically every 7,500-10,000 miles (12,000-16,000 km) or annually, depending on driving conditions and oil used. Fuel Filter Replacement: Recommended every 15,000-20,000 miles (24,000-32,000 km). Air Filter Replacement: Recommended annually or every 15,000 miles (24,000 km). Fluid Specifications Engine Oil Spec: API CD or higher...