🏷️ Basic Information Identification Make: Mercedes-Benz Model: 300TD Model Code: W123 Series Codes Chassis Code: W123 Engine Code: OM617 (Diesel) 👋 Introduction Market Position Positioning: The Mercedes-Benz 300TD (W123 diesel variants) was positioned as a durable, luxurious, and fuel-efficient mid-size executive car, renowned for its robust engineering and longevity. Competitive Analysis Competitors: Competed with other European luxury sedans and estates from brands like BMW, Audi, Volvo, and Jaguar during its production run. Its diesel engine offered a distinct advantage in fuel economy. Key Features Unique Selling Points: Legendary Mercedes-Benz build quality, the reliable OM617 five-cylinder diesel engine, exceptional ride comfort, advanced safety features for its era, and impressive durability. 📋 Manual Details Coverage Areas Applicable Years: 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985 Body Styles: Sedan, Coupe, Wagon (Estate/T-Model), potentially Limousine variants Page Count Estimated Page Count: 1000+ Manual Type Type: Service and Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Powertrain: Engine (OM617 diesel), Fuel System, Exhaust System, Cooling System, Lubrication System, Starting System, Charging System Drivetrain: Manual Transmission, Automatic Transmission, Driveshafts, Differentials, Axles Chassis: Suspension (front and rear), Steering System, Brake System (hydraulic, front disc, rear drum/disc), Wheel Bearings Electrical: Wiring Diagrams, Lighting System, Ignition System, Instruments and Gauges, Power Accessories, Fuses and Relays, Battery Body And Interior: Body Panels, Doors, Windows, Seats, Trim, HVAC System (Heating, Ventilation, Air Conditioning), Convertible Tops (if applicable) Procedures Included Maintenance: Oil Changes, Filter Replacements, Fluid Checks and Replacements, Belt Inspections and Adjustments, Spark Plug Replacement (for gasoline variants), Glow Plug Checks Troubleshooting: Diagnostic Procedures for common issues, symptom-based troubleshooting guides Repair: Component Removal and Installation, Engine Overhaul, Transmission Rebuilds, Brake System Overhaul, Suspension Component Replacement, Electrical Component Diagnosis and Repair Technical Depth Depth: Comprehensive, covering routine maintenance, diagnostics, and in-depth mechanical and electrical repairs. Suitable for professional mechanics and experienced DIY enthusiasts. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely text-searchable, allowing for quick access to specific information Print Quality Quality: High-resolution scans, ensuring clarity of diagrams and text Binding Type Type: N/A (Digital Download) Paper Type Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Inline 5-cylinder, naturally aspirated Diesel Engine Code: OM617.912 (typically) Displacement: 3.0 Liters (2998 cc) Performance Horsepower: Approx. 77-83 hp (depending on specific market/tuning) Torque: Approx. 130-137 lb-ft (176-186 Nm) at around 2400 RPM Fuel System Injection Type: Bosch Inline Fuel Injection Pump Fuel Type: Diesel Cooling System Coolant Type: Mercedes-Benz Specification Coolant (e.g., MB 325.0 or equivalent blue/green glycol-based antifreeze) Lubrication System Oil Type: API CD or CE rated Diesel Engine Oil, SAE 15W-40 or 10W-30 depending on climate Oil Capacity: Approx. 7.5 Liters (with filter) Ignition System Glow Plugs: Pre-combustion chamber type glow plugs, crucial for cold starts 🔧 Transmission Standard Type: 4-speed Manual Transmission (often) Optional Type: 4-speed Automatic Transmission (e.g., 4G-Tronic) Features Automatic Transmission Fluid: Dexron II or equivalent ATF 📐 Dimensions Exterior Length: Approx. 4725-4750 mm (Sedan) Width: Approx. 1790 mm Height: Approx. 1420-1440 mm (Sedan) Weights Curb Weight: Approx. 1450-1600 kg (depending on body style and equipment) 🛡️ Safety Features Ratings Crash Safety: Designed to meet rigorous safety standards of its era; featured crumple zones and reinforced passenger cell. Specific NHTSA/Euro NCAP ratings may not be directly available for this vintage. Active Features Braking: Power-assisted front disc brakes, rear drum brakes (later models may have rear discs). Anti-lock Braking System (ABS) became available on some later W123 models, though less common on the 300TD. Passive Features Restraints: Seat belts (lap belts in front, potentially three-point in rear depending on year/market), padded dashboard, collapsible steering column. 💡 Technology Features Infotainment Audio System: Factory fitted AM/FM radio with cassette player (often optional or upgraded later). Speakers located in doors and rear parcel shelf. Driver Assistance Cruise Control: Available as an option on many models. Connectivity Availability: N/A (No factory connectivity features like Bluetooth or USB as standard for this era). 🔧 Maintenance Service Intervals Oil And Filter Change: Every 5,000 - 10,000 km or 6-12 months (refer to manual for precise interval based on driving conditions) Air Filter Replacement: Every 20,000 - 30,000 km or as needed based on environment Fuel Filter Replacement: Every 20,000 - 40,000 km or as needed Coolant Flush: Every 2-3 years or as recommended Fluid Specifications Brake Fluid: DOT 3 or DOT 4 Brake Fluid Power Steering Fluid: ATF Dexron II or equivalent Known Issues Common Problems: Rust (especially wheel arches, rocker panels, jacking points), Injector pump seals (OM617), Glow plug issues, Vacuum leaks, Heater control valve failures, Potential for oil cooler leaks. Diesel Specific Issues: Injector pump timing, fuel system bleeding after filter changes, cold start reliability if glow plug system is not maintained. Part Numbers Oil Filter Example: Mann-Filter MH 120 / MB Part No. 000 180 2309 (example, verify for specific...