🏷️ Basic Information

Make:

Mercedes-Benz

Model:

114 / 115 Series

Model Aliases:

W114, W115, /8 Series, Stroke Eight

Production Years:

1968-1973 (W114), 1968-1976 (W115)

Chassis Codes:

W114, W115

👋 Introduction

Segment:

Mid-size luxury sedan and coupe, positioned as a more accessible entry into Mercedes-Benz ownership while retaining premium build quality and engineering.

Competitors:

Competed with vehicles like the BMW E3 Neue Klasse, Audi 100, Volvo 140 Series, and other European luxury and executive sedans of the era.

Design Philosophy:

Emphasized robust engineering, long-term durability, advanced safety features for its time, and sophisticated ride comfort, embodying Mercedes-Benz's reputation for quality.

Body Styles:

Offered as a four-door sedan (W115) and a two-door coupe (W114), later a longer wheelbase sedan was also available.

📋 Manual Details

Coverage Scope:

Comprehensive workshop service and repair for Mercedes-Benz W114 and W115 models.

Estimated Pages:

Likely 500+ pages (typical for comprehensive factory-style manuals).

Type:

Workshop Service Repair Manual

Language:

English (presumed, as most widely distributed manuals of this era for export markets were in English).

Format:

PDF (Digital)

📖 Manual Coverage

Engine:

Detailed coverage of all gasoline (M114, M115) and diesel (OM601, OM602, OM615, OM616) engines, including overhaul, timing, fuel injection systems, lubrication, cooling, and exhaust.

Transmission:

Manual and automatic transmission service, repair, overhaul, clutch, and drive shaft components.

Brakes:

Hydraulic brake system (front discs, rear drums), parking brake, brake fluid, master cylinder, wheel cylinders, calipers, and ABS if applicable to later variants.

Suspension:

Front independent suspension (double wishbone), rear semi-trailing arm suspension, shock absorbers, springs, ball joints, bushings, and steering components.

Electrical:

Complete electrical system, wiring diagrams, ignition system, starting system, charging system (alternator/generator), lighting, instrumentation, fuses, relays, and accessories.

Body:

Body shell construction, door mechanisms, window regulators, trim, bumpers, glass replacement, interior components, and underbody protection.

HVAC:

Heating system, ventilation, and optional air conditioning system diagnosis and repair.

Maintenance:

Routine maintenance schedules, oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, tune-ups, and belt adjustments.

Repair:

Detailed step-by-step repair procedures for all major mechanical and electrical components, including engine rebuilds, transmission overhaul, brake caliper replacement, suspension arm replacement, and electrical component diagnostics.

Troubleshooting:

Diagnostic charts and troubleshooting guides for common and uncommon problems, helping to identify causes and solutions.

Diagnostics:

Procedures for diagnosing faults in the engine, fuel, ignition, electrical, and mechanical systems.

Adjustments:

Precise specifications and procedures for adjusting valve clearances, ignition timing, carburetor settings, idle speed, and clutch pedal free play.

Fuel System Repair:

Detailed procedures for carburetor overhaul and adjustment, fuel pump replacement, fuel line repair, and fuel tank cleaning/servicing.

Ignition System Diagnosis:

Step-by-step troubleshooting for ignition timing, distributor, coil, spark plugs, and wiring for reliable starting and running.

Cooling System Maintenance:

Radiator, water pump, thermostat, hoses, and fan clutch inspection, replacement, and coolant flush procedures.

Steering And Suspension Alignment:

Specifications and procedures for wheel alignment, tie rod end replacement, ball joint inspection, and bushing replacement.

Electrical Component Replacement:

Guides for replacing starter motors, alternators, voltage regulators, wiper motors, headlights, and dashboard instruments.

Depth Level:

Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds, suitable for professional mechanics and experienced DIY enthusiasts.

Engine Rebuild:

Includes detailed specifications for bore, hone, piston ring gap, bearing clearances, and torque sequences for complete engine overhauls.

Transmission Rebuild:

Procedures for disassembling, inspecting, and reassembling manual and automatic transmissions, including gear replacement and seal installation.

Bodywork Repair:

Information on body panel alignment, rust repair techniques, and interior trim component removal/installation.

Wiring Diagrams:

Full vehicle wiring schematics for all major electrical systems, crucial for diagnosis and repair.

📊 Manual Specifications

Quality:

High-resolution PDF with searchable text and clear, legible diagrams. Printable pages.

Diagrams:

Detailed line drawings, exploded views, and schematics are expected to be high quality and accurate.

Binding:

Not Applicable (Digital PDF)

Paper:

Not Applicable (Digital PDF)

⚙️ Engine Specifications

Gasoline Options:

M114: 2.3L inline-6 (114.980), M115: 2.0L inline-4 (115.912, 115.914), 2.3L inline-4 (115.917)

Diesel Options:

OM601: 2.0L inline-4 diesel (W115 variant), OM615: 2.2L inline-4 diesel (60 hp), OM616: 2.4L inline-4 diesel (65 hp), later OM615.940 2.0L and OM616.912 2.2L diesel engines.

Horsepower Range:

Approx. 90 hp (2.0L diesel) to 140 hp (2.5L gasoline).

Torque Range:

Approx. 120 lb-ft (2.0L diesel) to 150 lb-ft (2.5L gasoline).

Gasoline Induction:

Carburetor (e.g., Solex, Zenith) for most models; fuel injection (Bosch D-Jetronic or similar) on some later or higher-performance variants.

Diesel Injection:

Bosch inline injection pump.

Block Material:

Cast Iron

Head Material:

Aluminum Alloy

Type:

Water Cooled, Thermostatic Control

🔧 Transmission

Type:

4-speed Manual Transmission (floor or column shift)

Type:

3-speed or 4-speed Automatic Transmission (e.g., 'Hydrak', 'TorqueFlite' based)

Clutch:

Single dry plate, hydraulically actuated.

Drive Axle:

Rear-wheel drive, with universal joints and a differential.

📐 Dimensions

Wheelbase Sedan:

Approx. 2710 mm (106.7 inches)

Wheelbase Coupe:

Approx. 2710 mm (106.7 inches)

Length Sedan:

Approx. 4700 mm (185.0 inches)

Length Coupe:

Approx. 4670 mm (183.9 inches)

Curb Weight Range:

Approx. 1300-1500 kg (2866-3307 lbs) depending on engine and equipment.

🛡️ Safety Features

Safety Standards:

Designed to meet stringent safety standards of the era, featuring crumple zones, a safety cell, and padded interior.

Braking System:

Power-assisted disc brakes front, drum brakes rear. Optional ABS was not common for this generation.

Steering:

Recirculating ball steering, optional power steering available on many models.

Seatbelts:

Standard front seatbelts, optional rear seatbelts.

Occupant Protection:

Reinforced passenger cell, energy-absorbing steering column, padded dashboard.

💡 Technology Features

Features:

Basic AM/FM radio with manual tuning; optional power antenna. No advanced infotainment systems as per modern standards.

Features:

No electronic driver assistance systems. Focus on mechanical systems and driver control.

Features:

No digital connectivity features. Primarily analog systems.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000 - 8,000 km (3,000 - 5,000 miles) or 6-12 months, depending on driving conditions and oil used.

Tune Up Interval:

Spark plugs, ignition points, and condenser every 10,000 - 20,000 km (6,000 - 12,000 miles). Valve adjustment as per manual (e.g., 15,000 - 25,000 km).

Engine Oil:

API SF/SG or equivalent. Viscosity: 10W-40, 15W-40, or 20W-50 depending on climate. (Consult manual for precise MB specs).

Coolant:

Ethylene glycol based antifreeze/coolant. 50/50 mix with distilled water recommended. Capacity varies by engine (approx. 6-8 liters).

Brake Fluid:

DOT 3 or DOT 4 hydraulic brake fluid.

Transmission Fluid Auto:

Dexron II or equivalent automatic transmission fluid (ATF).

Transmission Fluid Manual:

GL-4 Hypoid gear oil, SAE 80W-90.

Differential Fluid:

GL-5 Hypoid gear oil, SAE 80W-90.

Common Problems:

Rust (particularly wheel arches, sills, underbody), aging rubber components (bushings, hoses, mounts), vacuum leaks, carburetor issues, fuel system deterioration (especially with ethanol in fuel), potential overheating if cooling system is neglected, wear in suspension and steering components.

📚 Vehicle History

Legacy:

Represents Mercedes-Benz's commitment to building durable, high-quality vehicles that offer excellent longevity and comfort, building on the success of the 'Ponton' and 'Fintail' generations.

Introduction Era:

Introduced as a replacement for the W108/W109 S-Class entry points, offering a more compact and modern design. The W115 focused on the four-cylinder engines, while the W114 featured the six-cylinder engines.

Facelift:

Received minor updates throughout its production run, including interior trim revisions and engine enhancements.

Manufacturing Locations:

Primarily Germany (Sindelfingen) and also produced in other global facilities under license or assembly.

Total Units Produced:

Over 1.9 million units combined for W114 and W115, making it a very successful model for Mercedes-Benz.

🏆 Awards & Recognition

Industry Acclaim:

Widely recognized for its robust build quality, exceptional durability, and comfortable ride, which cemented Mercedes-Benz's reputation for engineering excellence during the 1970s.

Reliability:

Generally considered highly reliable and durable when properly maintained, often exceeding 300,000 miles with rebuilds.