🏷️ Basic Information Identification Make: Mercedes-Benz Model: 300CD Year: 1985 Body Style: Coupe Codes Chassis Code: W123 Engine Code: OM617.952 👋 Introduction Market Position Segment: Mid-size Luxury Coupe / Sedan Era: Iconic 1980s Mercedes-Benz Competitive Analysis Competitors: BMW 3 Series, Audi Coupe, Volvo 240 Series Usp: Robust engineering, diesel efficiency, legendary build quality Key Features Vehicle Philosophy: Durability, performance, refined comfort, understated luxury Manual Benefit: Empowers owners and technicians with the knowledge to maintain and repair this classic vehicle accurately. 📋 Manual Details Coverage Areas Primary Focus: Workshop Service and Repair Target Audience: Professional Technicians and Experienced DIYers Page Count Estimated Pages: 500+ Manual Type Type: Service and Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Mechanical: Complete overhaul, component testing, timing, fuel injection system Engine Electrical: Ignition, starting system, charging system, sensors Fuel System: Diesel injection pump, injectors, fuel lines, filters, glow plug system Transmission: Automatic transmission service, fluid changes, general troubleshooting Drivetrain: Driveshaft, differentials, axle shafts Suspension: Front and rear suspension components, shock absorbers, springs, control arms Steering: Power steering system, steering linkage, steering column Brakes: Hydraulic system, disc and drum brakes, parking brake, ABS (if equipped) Electrical System: Wiring diagrams, lighting, instrumentation, accessories, power windows, central locking HVAC: Heating, ventilation, air conditioning system service Body And Chassis: Body panels, doors, windows, interior trim, chassis lubrication Procedures Included Maintenance: Scheduled maintenance, fluid checks, filter replacements, lubrication Troubleshooting: Diagnostic procedures, symptom-based troubleshooting, fault codes Repair: Step-by-step repair instructions for all major components and systems Diagnostics: Detailed diagnostic trees, component testing procedures, electrical troubleshooting Technical Depth Depth: Comprehensive, from basic maintenance to complete engine and transmission rebuilds Detail Level: Includes torque specifications, alignment data, and diagnostic flowcharts 📊 Manual Specifications File Format Format: PDF Searchability: Text-searchable (OCR) Print Quality Quality: High-resolution scans of original factory documentation Binding Type Binding: Not applicable (Digital Download) Paper Type Paper: Not applicable (Digital Download) ⚙️ Engine Specifications Primary Engine Type: Inline 5-Cylinder Diesel with Turbocharger Displacement: 2998 cc (3.0 Liters) Bore X Stroke: 87.0 mm x 92.3 mm Compression Ratio: 21.0:1 Performance Horsepower: 90 hp @ 4350 rpm Torque: 125 lb-ft @ 2400 rpm Fuel System Injection System: Bosch Inline Injection Pump (M-type) Fuel Type: Diesel Glow Plugs: Yes, pre-heating system Lubrication Oil Type Specification: API CD or ACEA B2, SAE 15W-40 (or 10W-30 in very cold climates) Cooling System Coolant Type: Ethylene Glycol based, 50/50 mix with distilled water 🔧 Transmission Standard Type: 4-Speed Automatic (4G-TRONIC) Optional Type: 5-Speed Manual (Less Common in US Market) Features Automatic Modes: Economy (E) and Sport (S) modes Fluid Specification Automatic Transmission Fluid: MB 236.1 Specification (e.g., ATF Dexron III is often a suitable substitute, but check manual for exact spec) 📐 Dimensions Exterior Length: 188.0 inches (4775 mm) Width: 68.5 inches (1740 mm) Height: 55.5 inches (1410 mm) Wheelbase: 108.7 inches (2760 mm) Weights Curb Weight: 3515 lbs (1595 kg) Gross Vehicle Weight Rating: 4475 lbs (2030 kg) 🛡️ Safety Features Ratings NHTSA Front Impact: Not rated (Vehicle predates modern comprehensive testing) Active Features ABS: Optional (available on higher trims or later models) Passive Features Airbags: Driver's airbag optional, not standard Seatbelts: 3-point front seatbelts, lap belts in rear Crumple Zones: Designed with energy-absorbing zones 💡 Technology Features Infotainment Audio System: Factory AM/FM radio with cassette player (optional). Climate Control: Manual climate control with optional automatic climate control. Driver Assistance Cruise Control: Standard on most models. Connectivity Phone Integration: None (aftermarket solutions available). 🔧 Maintenance Service Intervals Oil And Filter Change: Every 5,000 - 7,500 miles or annually (refer to manual for exact recommendation) Fuel Filter Replacement: Every 15,000 - 20,000 miles Air Filter Replacement: Every 15,000 - 20,000 miles Valve Adjustment: Every 30,000 - 45,000 miles Fluid Specifications Engine Oil Capacity: 7.5 Liters (7.9 Quarts) Coolant Capacity: 10.5 Liters (11.1 Quarts) Brake Fluid: DOT 3 or DOT 4 (Check manual for precise specification) Known Issues Common Problems: Valve cover gasket leaks, vacuum hose degradation, idle control issues, potential for injector pump issues if not properly maintained. Diesel Specific: Glow plug system reliability, fuel system maintenance is critical for longevity. Technical Tips Idle Speed Adjustment: Requires understanding of injection pump linkage and vacuum controls. 📚 Vehicle History Brand Heritage Mercedes Benz Legacy: Pioneering automotive manufacturer with a focus on engineering excellence and longevity. Model Evolution W123 Generation: Part of the highly regarded W123 series (1976-1985), known for its exceptional build quality and durability. 300Cd Variant: Coupe version of the popular 300D sedan, offering a sportier profile. Production Production Years: 1977-1985 (for W123 Coupes, 1981-1985 for 300CD in North America) Manufacturing Location: West Germany 🏆 Awards & Recognition Recognitions Legacy Perception: Consistently ranked among the most reliable and durable Mercedes-Benz models ever produced. Ratings Consumer Reports Reputation: Highly praised for reliability and longevity in period reviews. Certifications Manual Validation: Represents...