🏷️ Basic Information Identification Make: Mercedes-Benz Model: W123 E-Class Model Variant: E-Class Year: 1978 Codes Chassis Code: W123 Platform: W123 👋 Introduction Market Position Market Position: The W123 chassis represented Mercedes-Benz's mid-size luxury and executive car offering, known for exceptional build quality, durability, and comfort. Competitive Analysis Competitors: Competed with other European executive sedans like the BMW 5 Series (E12), Audi 100, Volvo 240, and Jaguar XJ6. Key Features Key Features: Renowned for robust engineering, longevity, solid ride quality, and sophisticated design for its era. Manual Value Proposition: Provides definitive, accurate information for maintaining and repairing a classic Mercedes-Benz, essential for preserving its value and performance. 📋 Manual Details Coverage Areas Vehicle Coverage: All W123 E-Class models produced for the 1978 model year. Page Count Page Count: Detailed page count not specified, but described as comprehensive covering all repairs A-Z. Manual Type Manual Type: Factory Service and Repair Manual Language Language: English Format Format: Likely printed document or digital format (e.g., PDF) commonly distributed to dealerships. 📖 Manual Coverage Systems Covered Engine Systems: Engine mechanical, fuel delivery, ignition system, cooling system, lubrication system, emissions control. Transmission Systems: Manual and automatic transmission service, repair, and diagnosis. Drivetrain Systems: Clutch, driveshaft, differential, axles, wheel bearings. Suspension And Steering: Front and rear suspension components, steering gear, power steering system, alignment procedures. Brake Systems: Hydraulic brake system, front and rear disc/drum brakes, parking brake, brake fluid specifications. Electrical Systems: Wiring diagrams, lighting, charging system (alternator), starting system (starter motor), battery, instrumentation, auxiliary circuits. Body And Chassis: Body panel removal and installation, doors, windows, interior trim, chassis lubrication, rust prevention. HVAC Systems: Heating system, ventilation, and air conditioning (if equipped) service and repair. Fuel Tank And Exhaust: Fuel tank, fuel lines, exhaust system components. Procedures Included Maintenance Procedures: Oil change, filter replacement, fluid checks and top-offs, spark plug replacement, belt inspection and tensioning. Troubleshooting Guides: Diagnostic procedures for common and uncommon issues across all systems. Repair Procedures: Step-by-step instructions for component removal, overhaul, and installation for all major vehicle systems. Diagnostic Procedures: Detailed diagnostic trees and symptom-based troubleshooting. Adjustment Procedures: Valve adjustments, idle speed adjustments, brake adjustments, clutch adjustments. Specification Charts: Torque specifications, clearances, fluid capacities, electrical values. Wiring Diagrams: Complete electrical wiring schematics for all vehicle circuits. Technical Depth Depth: Technician-level detail, covering from basic maintenance to complete engine rebuilds, complex electrical diagnostics, and bodywork. Accuracy: Vehicle-specific and dealership-level accuracy, not generic information. 📊 Manual Specifications File Format File Format Quality: Presumed to be high-quality, easily readable for technicians. If digital, likely searchable PDF. Print Quality Print Quality Expectation: Original dealership manuals typically feature clear diagrams, crisp text, and durable paper. Binding Type Binding Type Expectation: Original manuals often use sturdy bindings like spiral, comb, or perfect binding for lay-flat usability. Paper Type Paper Type Expectation: Typically printed on durable, often semi-gloss paper to withstand workshop conditions. ⚙️ Engine Specifications Primary Engine Engine Options 1978: While the product name specifies 'E', the W123 chassis offered various gasoline and diesel engines. Common gasoline engines for 1978 included the 2.5L inline-4 (M115 variants) and 2.8L inline-6 (M110 variants). Diesel options included the 2.4L inline-4 (OM615) and 3.0L inline-5 (OM617). Performance Horsepower Range: Varies by engine; typically from 70 hp (diesel) to 140 hp (petrol inline-6) for 1978 models. Torque Range: Varies by engine; diesel engines provided strong low-end torque. Fuel System Fuel Delivery Gasoline: Carbureted (e.g., Zenith, Solex) or Bosch K-Jetronic fuel injection depending on engine variant. Fuel Delivery Diesel: Bosch inline injection pumps. Engine Code Examples Engine Codes: M115.95x (2.5L gasoline), M110.98x (2.8L gasoline), OM615.94x (2.4L diesel), OM617.91x (3.0L diesel). 🔧 Transmission Standard Standard Transmission: Often a 4-speed or 5-speed manual transmission. Optional Optional Transmission: 3-speed or 4-speed automatic transmission (e.g., 722.1 or 722.3 series). Features Transmission Features: Robust and durable units, with automatic transmissions often featuring a torque converter. 📐 Dimensions Exterior Body Styles: Sedan (4-door), Coupe (2-door), Estate/Wagon (T-model). Length Sedan Approx: Approx. 4725 mm (186 in) Wheelbase Approx: Approx. 2790 mm (110 in) Weights Curb Weight Range: Approx. 1350-1550 kg (2976-3417 lbs) depending on body style and engine. 🛡️ Safety Features Ratings Safety Era Standards: Designed to high European safety standards of the late 1970s, featuring a reinforced safety cell, collapsible steering column, and impact-absorbing zones. Active Features Active Safety Features: Four-wheel disc brakes (on some models), power-assisted steering, independent suspension. Passive Features Passive Safety Features: Collapsible steering column, reinforced roof structure, laminated front windshield, safety glass elsewhere. 💡 Technology Features Infotainment Infotainment Systems: Basic AM/FM radio, with optional cassette players. Primarily focused on core vehicle functions, not extensive entertainment systems. Driver Assistance Driver Assistance Features: Limited by era; features like power steering, automatic transmission, and cruise control (optional) were the primary aids. Connectivity Connectivity Features: No electronic connectivity features as understood today. Focus on mechanical and basic electrical systems. Lighting Lighting...