🏷️ Basic Information Identification Make: Mercedes-Benz Model: 450 SEL Chassis Code: W116 Model Years Covered: 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980 Codes Engine Code Primary: M117 👋 Introduction Market Position Target Segment: Luxury Sedan Era: Early to late 1970s luxury automotive segment Competitive Analysis Competitors Era: BMW E23 7 Series, Jaguar XJ, Cadillac Fleetwood, Lincoln Continental Key Features Vehicle Focus: Luxury, comfort, engineering, advanced features for its time Manual Purpose: Empower owners and technicians to perform expert-level maintenance and repairs, maximize vehicle value 📋 Manual Details Coverage Areas Coverage Scope: Comprehensive workshop service and repair Target Audience: Mechanical technicians, experienced DIY enthusiasts Page Count Estimated Page Count: Extensive (Exact count not specified, but described as complete) Manual Type Type: Workshop Service Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Systems: Engine disassembly, assembly, tune-ups, lubrication, cooling, fuel, ignition, exhaust Drivetrain Systems: Transmission (engine and transmission disassembly for repair/overhaul) Electrical Systems: Full electrical system diagnosis and repair, ignition system Chassis Systems: Brakes, steering, suspension (implied by workshop coverage) Body Systems: Body repair and maintenance procedures Procedures Included Maintenance Procedures: Routine maintenance, servicing, tune-ups Repair Procedures: Diagnostic and repair procedures for various systems, overhaul of major components Installation Procedures: Removal and installation procedures for components and assemblies Troubleshooting: Diagnostic procedures for common and complex issues Technical Depth Depth: Detailed, emphasizing special aspects of the product, includes proprietary component information 📊 Manual Specifications File Format File Type: PDF Printability: Yes Searchability: Implied by PDF format, likely text-searchable Delivery Delivery Method: Electronic delivery via Email Delivery Speed: Fast Binding Type Binding: N/A (Digital format) Paper Type Paper Type: N/A (Digital format) ⚙️ Engine Specifications Primary Engine Engine Type: V8, Four-stroke internal combustion Engine Displacement Liters: 4.5 Engine Displacement Cubic Inches: 276 Performance Horsepower Approx Net: 220-230 hp (SAE Net, specific to year/market variations) Torque Approx Net Lb Ft: 270-280 lb-ft (SAE Net, specific to year/market variations) Fuel System Fuel Delivery: Bosch K-Jetronic Fuel Injection (for most later models and common variants) Fuel Type: Unleaded Gasoline 🔧 Transmission Standard Type: Automatic Model: Mercedes-Benz 3-speed Automatic (e.g., 4G-Tronic) Optional Availability: Manual transmissions were extremely rare or not offered on the 450 SEL in North America. Features Transmission Cooling: Integrated transmission fluid cooler (typically via radiator) 📐 Dimensions Exterior Wheelbase Inches: 116.7 inches (approx.) Overall Length Inches: 199.9 inches (approx.) Overall Width Inches: 70.5 inches (approx.) Weights Curb Weight Lbs: 3900 - 4200 lbs (approx.) 🛡️ Safety Features Ratings Safety Features Era: Advanced for its time: Crumple zones, safety steering column, reinforced cabin, laminated windshield Active Features Brakes: Power-assisted 4-wheel disc brakes, often with ABS (Anti-lock Braking System) on later models (e.g., 1978 onwards) Passive Features Seatbelts: Front and rear seatbelts 💡 Technology Features Infotainment Audio System: Factory AM/FM radio, often with cassette player as an option. Soundproofing for a quiet cabin was a key feature. Driver Assistance ABS: Anti-lock Braking System (ABS) available on later models, a significant technological advancement for the time. Climate Control HVAC: Advanced (for the era) automatic climate control system with air conditioning and heating. Comfort Features Power Features: Power windows, power locks, power steering, power seats (often with memory function), cruise control. 🔧 Maintenance Service Intervals Oil Change Interval Miles: Every 5,000 - 7,500 miles (or 6-12 months, depending on driving conditions and oil type used, consult manual for specifics) Tune Up Interval: As needed or every 20,000 - 30,000 miles, focus on ignition timing, fuel mixture, and spark plugs. Fluid Specifications Engine Oil Type: API SG or higher, SAE 10W-40 or 15W-40 recommended (consult manual for exact viscosity based on climate). Transmission Fluid Type: Dexron III (or equivalent) automatic transmission fluid Coolant Type: Ethylene Glycol based coolant, typically a 50/50 mix with distilled water. Known Issues Common Wear Items: Fuel injection components (e.g., injectors, fuel distributor), vacuum lines, climate control system, suspension bushings, fuel pump. Electrical Gremlins: While generally robust, aging wiring harnesses and connections can lead to intermittent electrical issues. The manual's diagnostic section is crucial here. Corrosion: As with many cars of this era, rust and corrosion in common areas (wheel arches, rocker panels, underbody) can be an issue depending on climate and care. 📚 Vehicle History Brand Heritage Heritage: Mercedes-Benz reputation for engineering excellence, safety, and durability. Model Evolution W116 Introduction: The W116 was Mercedes-Benz's first true 'S-Class' designation, replacing the W108/W109 series and setting the standard for modern luxury sedans. W116 Variants: Included the 280 S, 280 SE, 350 SE, 450 SE, 450 SEL (long wheelbase), and the performance-oriented 450 SLC coupe. Production Production Years: 1972-1980 Production Location: Germany (primarily Sindelfingen) 🏆 Awards & Recognition Recognitions Industry Impact: The W116 series established the 'S-Class' benchmark for luxury, safety, and technological innovation, influencing luxury car design for decades.