🏷️ Basic Information Identification Make: Mercedes-Benz Model: W114 / W115 Year: 1974 Generation Chassis Code: W114 (Luxury Sedan/Coupe), W115 (Standard Sedan/Diesel) Codes Model Series: Mid-size luxury automobile 👋 Introduction Market Position Vehicle Segment: Mid-size executive sedans and coupes, positioned as premium vehicles in their era. Competitive Analysis Key Competitors: BMW 5 Series, Audi 100, Volvo 140 Series, Jaguar XJ6, American large sedans (though positioned differently). Key Features Manual Advantage: Provides exact, vehicle-specific information used by dealership technicians, ensuring accuracy and completeness unlike generic repair guides. Digital Convenience: All-in-one, searchable PDF manual eliminating the need for multiple physical books. Allows selective printing and digital storage. 📋 Manual Details Coverage Areas Primary Coverage: All models and all repairs A-Z for 1974 Mercedes-Benz W114 and W115 Specific Topics: Maintenance, Engine, Control System, Mechanical, Fuel Service, Emission Control, Intake/Exhaust, Cooling, Lube, Ignition, Starting, Charging, Automatic Transmission, Clutch, Manual Transmission, Transfer Case, Propeller Shaft, Drive Shaft, Differential, Axle, Suspension, Tires, Wheels, Brake Control, Parking Brake, Steering Column, Power Steering, Air Conditioning, Supplemental Restraint System (if applicable), Seat Belts, Engine Immobilizer (if applicable), Cruise Control, Wiper/Washer, Door Locks, Meter, Audio/Visual, Horn, Windshield/Glass/Mirrors, Instrument Panel, Seats, Engine Hood/Doors, Exterior/Interior Trim, Electrical Systems, Multiplex/CAN Communication (limited applicability for this era) Page Count Estimated Page Count: Extensive (exact number not specified, but implied to be comprehensive for A-Z repairs) Manual Type Type: Factory Service and Repair Manual Language Language: English Format Digital Format: PDF 📖 Manual Coverage Systems Covered Powertrain: Engine (gasoline and diesel variants), Fuel System, Cooling System, Lubrication System, Ignition System, Starting System, Charging System, Exhaust System, Automatic Transmission, Manual Transmission, Clutch, Driveshafts, Differential, Axles. Chassis And Suspension: Front and Rear Suspension, Steering System (including power steering), Wheels, Tires, Brakes (front and rear, including parking brake). Electrical And Body: Wiring Schematics, Lighting, Instruments, Gauges, Wipers, Horn, Power Windows (if equipped), Door Locks, Air Conditioning, Heating, Exterior and Interior Trim, Body Panels. Procedures Included Maintenance: Scheduled maintenance, fluid changes, lubrication, filter replacements, tune-ups, inspections. Diagnostics And Troubleshooting: System-specific diagnostic procedures, fault finding, symptom-based troubleshooting, diagnostic charts. Repair And Rebuild: Step-by-step instructions for component removal, disassembly, repair, assembly, and reinstallation for major vehicle systems. Technical Depth Detail Level: Factory-level detail, intended for professional technicians. Includes torque specifications, clearances, timing settings, component identification, and diagnostic procedures. 📊 Manual Specifications File Format Digital Container: PDF (Portable Document Format) Print Quality Printable Resolution: High-resolution, allowing for clear printing of diagrams and text. Images can be enlarged for detailed viewing. Binding Type Digital Format Benefit: N/A (Digital format, not physically bound) Paper Type Digital Format Benefit: N/A (Digital format, printable on user's choice of paper) ⚙️ Engine Specifications Primary Engine Engine Options 1974: W114: M115 (2.3L I4), M110 (2.8L I6). W115: OM615 (2.2L Diesel I4), OM616 (2.4L Diesel I4). Performance Horsepower Range: Approximately 90 HP (Diesel) to 140 HP (2.8L I6 Gasoline). Torque Range: Varies by engine, typically 120 lb-ft to 175 lb-ft. Fuel System Gasoline Induction: Carbureted (e.g., Solex, Zenith) for most models. Fuel injection (Bosch K-Jetronic) may be present on some higher-end gasoline variants. Diesel Injection: Direct injection with Bosch inline fuel injection pumps. 🔧 Transmission Standard Manual Transmission Type: 4-speed or 5-speed manual (column or floor shift). Optional Automatic Transmission Type: 3-speed automatic (historically known as 'Hydrak' for earlier models, likely upgraded to conventional torque converter automatics by '74). Features Transmission Control: Mechanical linkages for manual, hydraulic for automatic. 📐 Dimensions Exterior Wheelbase: W114: 108.3 inches (2750 mm). W115: 108.3 inches (2750 mm). Length: W114 Sedan: 187.4 inches (4760 mm). W115 Sedan: 187.4 inches (4760 mm). Weights Curb Weight: Approx. 3,000 - 3,400 lbs (1360 - 1540 kg), depending on engine and equipment. 🛡️ Safety Features Ratings Crash Test Era: Modern safety standards for the mid-1970s. Lacks advanced features like airbags or ABS found in later vehicles. Active Features Braking System: Front disc brakes, rear drum brakes. Power assist standard. Typically dual-circuit hydraulic system. Steering System: Recirculating ball steering, optional power steering. Passive Features Seatbelts: Standard front seat belts, with provision for rear seat belts. Body Construction: Unitized body construction with crumple zones and safety cage designed for the era. 💡 Technology Features Infotainment Audio System: Period-appropriate AM/FM radio, optional cassette player. Typically 1-2 speakers. Driver Assistance Cruise Control: Optional, vacuum-operated or early electronic systems available on some models. Connectivity Vehicle Systems: Basic electrical systems, no advanced digital networking like CAN bus. Focus on mechanical and analog electrical controls. 🔧 Maintenance Service Intervals Oil Change Interval: Typically every 3,000-5,000 miles (4,800-8,000 km) or annually, depending on driving conditions. Check manual for exact recommendation. Tune Up Interval: Spark plugs, ignition points (if applicable), and ignition timing checks generally recommended every 10,000-15,000 miles (16,000-24,000 km). Fluid Specifications Engine Oil Grade: API SF or SG classification. Viscosity typically SAE 10W-40 or 15W-40 depending on climate. Consult manual for precise OEM specifications. Coolant Type:...