🏷️ Basic Information Identification Make: Mercedes-Benz Model: 180 Series Model Variants: 180a, 180b, 180c Codes Chassis Code General: W121 Engine Code General: M121 👋 Introduction Market Position Vehicle Segment: Compact Executive Car / Luxury Sedan Target Audience: Buyers seeking reliable, well-engineered, and stylish compact luxury vehicles. Competitive Analysis Competitors: BMW 1800, Audi 100, Alfa Romeo Giulia. Key Features Brand Philosophy: Emphasizes engineering excellence, build quality, and durability. Design Philosophy: Elegant, understated styling with a focus on functionality and occupant comfort. Manual Value: Essential resource for owners and mechanics to maintain and repair these classic Mercedes-Benz models. 📋 Manual Details Coverage Areas Manual Type: Factory Service Repair Manual Language: English Format: PDF Download Completeness: Complete Official Factory Manual Page Count: Hundreds of Pages (Exact count may vary based on specific edition, but implies comprehensive coverage) 📖 Manual Coverage Systems Covered Engine Mechanical: Engine disassembly, assembly, inspection, repair, troubleshooting, component testing, cylinder head, block, crankshaft, camshaft, pistons, valves, timing system. Engine Fuel System: Carburetor(s) (e.g., Solex, Zenith), fuel pump, fuel filter, fuel lines, troubleshooting fuel delivery. Engine Ignition System: Distributor, ignition coil, spark plugs, points and condenser, timing adjustment, troubleshooting. Cooling System: Radiator, water pump, thermostat, hoses, fan, coolant specifications, troubleshooting overheating. Exhaust System: Exhaust manifold, exhaust pipes, muffler, catalytic converter (if applicable to later variants/markets), component replacement. Transmission Manual: Gearbox disassembly, assembly, inspection, repair, clutch operation, shift linkage, gear oil specifications. Transmission Automatic: Details on available automatic transmissions (if applicable), operation, maintenance, troubleshooting. Drivetrain Rear Axle: Differential, drive shafts, universal joints, axle ratios, lubrication, repair. Suspension Front: Independent front suspension, control arms, ball joints, coil springs, shock absorbers, steering linkage, wheel alignment specifications. Suspension Rear: Rear axle design (e.g., swing axle, independent), trailing arms, shock absorbers, springs, repair, lubrication. Braking System: Hydraulic system, master cylinder, wheel cylinders, brake shoes/pads, brake drums/rotors, brake fluid specifications, bleeding procedures, parking brake. Steering System: Steering box/rack, steering column, tie rods, idler arm, power steering (if equipped), lubrication, adjustments. Electrical System Charging: Generator/alternator, voltage regulator, battery specifications, wiring diagrams. Electrical System Lighting: Headlights, taillights, turn signals, interior lighting, bulb types, troubleshooting. Electrical System Instruments: Dashboard instruments (speedometer, tachometer, fuel gauge, temperature gauge), warning lights, wiring. Electrical System Accessories: Wipers, horn, radio, heater fan, cigarette lighter, power windows (if applicable). Body Exterior: Body panel removal/installation, doors, hood, trunk, fenders, bumpers, glass, trim, rust repair techniques. Body Interior: Seats, dashboard, door panels, headliner, carpets, insulation, trim components. Heating Ventilation Air Conditioning: Heater core, blower motor, ducting, controls, refrigerant (if AC equipped). Procedures Included Scheduled Maintenance: Oil changes, filter replacements, tune-ups, fluid checks, lubrication points, brake inspections, tire rotation. Troubleshooting: Diagnostic charts, symptom-based troubleshooting for various systems (engine, electrical, brakes, etc.). Repair Procedures: Step-by-step instructions for component removal, installation, and overhaul for all major vehicle systems. Disassembly Assembly: Detailed instructions for dismantling and reassembling engines, transmissions, axles, suspension, and body components. Adjustments: Carburetor adjustments, ignition timing, valve lash, brake adjustments, clutch adjustments, parking brake adjustments. Wiring Diagrams: Comprehensive electrical wiring diagrams for all vehicle systems, essential for diagnostics and repairs. Specifications Data: Torque specifications, clearances, fluid capacities, resistance values, engine data, and more. Technical Depth Depth: Comprehensive, suitable for professional mechanics and skilled DIY enthusiasts. Diagnostic Capabilities: Detailed troubleshooting guides and diagnostic procedures to identify and resolve problems. Rebuild Instructions: Instructions for complete engine, transmission, and differential rebuilds. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely searchable text-based PDF (depending on original scan quality). Print Quality Printability: Printable in its entirety or specific sections. Binding Type Binding: N/A (Digital Download) Paper Type Paper Quality: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Family: M121 Inline-4 Displacement Cc: Approx. 1790cc (varies slightly by specific variant and tuning). Bore X Stroke Mm: Typically 82.0 x 84.0 mm Compression Ratio: Around 8.0:1 to 8.5:1 (depending on variant). Performance Horsepower Ps: Around 75-85 PS (Gross) at ~4800-5000 rpm. Torque Nm: Around 125-135 Nm (Gross) at ~2800-3000 rpm. Fuel System Fuel Delivery: Single or dual downdraft carburetors (e.g., Solex 34 PAITA, Zenith 35 NDIX). Fuel Type: Premium Unleaded Gasoline (Octane rating appropriate for era, e.g., 91-94 RON). Lubrication Oil Capacity Liters: Approximately 5.0 - 5.5 Liters (including filter). Oil Specification: API SG or equivalent, viscosity typically SAE 10W-40 or 10W-30 depending on climate and preference. Consult manual for precise recommendations. 🔧 Transmission Standard Transmission Type: 4-speed Manual Optional Transmission Type: 3-speed Automatic (Optional on some variants, often a BorgWarner unit or Mercedes' own development). Features Clutch Type: Single dry plate, diaphragm spring. Transmission Fluid Spec: Manual: Gear oil GL-4 SAE 80W-90. Automatic: DEXRON II or equivalent (check specific requirements). 📐 Dimensions Exterior Wheelbase Mm: Approx. 2650 mm Length Mm: Approx. 4480 mm Width Mm: Approx. 1710 mm Height Mm: Approx. 1480 mm Weights Curb Weight Kg: Approx. 1200-1350 kg (depending on body style and equipment). Gross Vehicle Weight Kg: Approx. 1700-1800...