🏷️ Basic Information

Make:

Mercedes-Benz

Model:

W114/W115

Generation Name:

Stroke-8 (Neue Klasse)

Generation Years:

1968-1976

Chassis Code:

W114 (6-cylinder), W115 (4-cylinder)

👋 Introduction

Positioning:

The W114/W115 series, also known as the 'Stroke-8' or 'Neue Klasse', represented Mercedes-Benz's entry into the mid-size luxury sedan market, offering a balance of robust engineering, comfort, and reliability, becoming a global success.

Competitors:

Competed against vehicles like the BMW E116/E12, Audi 100, and Citroën DS in its respective market segments.

Distinguishing Features:

Monocoque construction (a first for Mercedes-Benz in this class), excellent ride comfort, robust drivetrain options (including the durable OM615/OM616 diesels), and a timeless design.

📋 Manual Details

Primary Coverage:

Workshop Service and Repair

Estimated Page Count:

Extensive (typical workshop manuals of this era are 500+ pages)

Type:

Digital Workshop Service Repair Manual

Language:

English

Format:

PDF, HTML (downloadable)

📖 Manual Coverage

Engine Mechanical:

Detailed procedures for engine disassembly, inspection, and reassembly, including torque specifications and clearances.

Engine Lubrication:

Covers oil pump, oil cooler, oil filter, lubrication passages, and oil pressure testing.

Engine Cooling:

Radiator, water pump, thermostat, coolant passages, fan operation, and pressure testing.

Engine Control:

Ignition system (points, condenser, coil, distributor), carburetion (Stromberg, Zenith, Solex depending on model), and fuel injection (Bosch D-Jetronic for some models).

Fuel System:

Fuel tank, fuel pump (mechanical/electric), fuel lines, filters, and carburetor/injection system maintenance and adjustment.

Exhaust System:

Exhaust manifolds, pipes, mufflers, catalytic converters (if applicable for later models), and mounting hardware.

Clutch:

Clutch disc, pressure plate, release bearing, flywheel, and hydraulic clutch system components and bleeding.

Manual Transmission:

Gearbox disassembly, rebuild, shifting mechanisms, and lubricant specifications.

Automatic Transmission:

Hydraulic control systems, torque converter, planetary gear sets, valve body, and fluid specifications for models like the 722.X series.

Front Axle:

Suspension components (control arms, ball joints, bushings), steering knuckles, wheel bearings, and alignment specifications.

Rear Axle:

Differential housing, drive shafts, U-joints, rear wheel bearings, and axle lubrication.

Front Suspension:

Independent front suspension design, shock absorbers, coil springs, sway bars, and mounting components.

Rear Suspension:

Semi-trailing arm rear suspension (W114/W115), shock absorbers, coil springs, bushings, and alignment.

Road Wheels And Tires:

Wheel specifications, tire pressure recommendations, and wheel alignment procedures.

Brake System:

Hydraulic disc brakes (front) and drum brakes (rear) or optional all-around discs, master cylinder, brake lines, calipers, wheel cylinders, and rotor/pad specifications.

Parking Brake:

Parking brake mechanism, cables, and adjustment procedures.

Brake Control System:

Brake booster (if equipped) operation and testing, proportioning valves.

Power Steering:

Hydraulic power steering system components (pump, steering box, hoses), fluid type, and troubleshooting.

Steering System:

Steering box, steering column, tie rods, and steering linkage components.

Seat Belts:

Installation, maintenance, and adjustment of seat belt systems.

Srs:

Not applicable for this generation; Supplemental Restraint Systems (airbags) were not standard or widely available.

Body Lock Security:

Door locks, ignition lock, trunk lock mechanisms, and key systems.

Glasses Windows Mirrors:

Window regulators, seals, door glass, windshield, rear window, and mirror installation and adjustment.

Roof:

Headliner, sunroof mechanisms (if equipped), and roof panel maintenance.

Exterior Interior:

Body trim, bumpers, interior panels, dashboard, seats, and carpeting.

Instrument Panel:

Gauges, warning lights, dashboard disassembly, and repair.

Air Conditioning:

Components of the A/C system (compressor, condenser, evaporator, blower), refrigerant types (R12 for this era), and system servicing.

Wiring Diagrams:

Comprehensive, high-quality electrical wiring diagrams for all vehicle systems, essential for diagnostics.

Starting Charging:

Starter motor, battery, alternator/generator operation, and testing.

Lighting System:

Headlights, taillights, turn signals, interior lighting, and bulb specifications.

Driver Information:

Instrument cluster functions, warning lamps, and trip computer (if equipped on later models).

Wiper Washer Horn:

Wiper motor, linkages, washer pump, and horn operation.

Body Control System:

Relays, fuses, and basic body electrical control modules (limited compared to modern vehicles).

Lan System:

Not applicable; Local Area Network systems were not present in vehicles of this era.

Audio Visual Navigation Telephone:

Radio installation and basic troubleshooting, early cassette players (optional).

Auto Cruise Control:

Operation and troubleshooting for optional cruise control systems.

Power Supply Ground Circuit Elements:

Battery management, grounding points, circuit protection (fuses, circuit breakers).

Preventative Maintenance:

Regular service checks, fluid changes, filter replacements, lubrication points.

Troubleshooting:

Systematic diagnostic procedures for common and uncommon faults, symptom-based fault finding.

Repair Rebuild:

Step-by-step instructions for component removal, overhaul, and reinstallation for all major vehicle systems.

Refurbishment Restoration:

Guidance on restoring original specifications, replacing worn components, and addressing age-related deterioration.

Depth:

Comprehensive; covers from basic adjustments to complete engine and transmission rebuilds, including detailed electrical schematics and torque values.

📊 Manual Specifications

File Type:

PDF

Image Quality:

High Quality Photos, Illustrations And Diagrams. Assumed to be clear and legible for printing.

Binding:

Digital Download (Not physically bound)

Paper Type:

Digital (printable on standard paper)

⚙️ Engine Specifications

Engine Variants Covered:

2.2L Inline-4 (M115), 2.0L Diesel Inline-4 (OM615), 2.4L Diesel Inline-4 (OM616), 2.5L Inline-6 (M114), 2.8L Inline-6 (M110), 3.0L Diesel Inline-5 (OM617).

Typical Horsepower Range:

Ranging from approximately 70 hp for the 220D to 130 hp for the 280/280C models. Specific output varied by year and emissions regulations.

Carburetor Types:

Stromberg 175CDT, Zenith 35/40 INAT, Solex 40 PDIT.

Fuel Injection Type:

Bosch D-Jetronic mechanical fuel injection for some gasoline models (e.g., 280E, 280CE).

🔧 Transmission

Standard Transmission:

4-speed manual transmission was standard on many models. 5-speed manual was optional on later models.

Optional Transmission:

3-speed automatic transmission (e.g., 722.1) was a popular option, particularly on higher-spec models.

Transmission Features:

Robust and durable transmissions, with clear procedures for fluid changes and seal replacement.

📐 Dimensions

Body Styles:

4-door Sedan (W114/W115), 2-door Coupe (C114/C115).

Wheelbase:

W114/W115: 2710 mm (106.7 in)

Curb Weight Range:

Approximately 1400-1600 kg (3100-3500 lbs) depending on engine and options.

🛡️ Safety Features

Crash Test Info:

Vehicle safety standards of the era were different; crash test ratings as understood today were not prevalent. Focus was on passive safety features inherent in Mercedes-Benz engineering.

Active Safety:

Four-wheel disc brakes (on some models), power steering, advanced suspension geometry for its time.

Passive Safety:

Collapsible steering column, reinforced safety cage, padded dashboard, and seat belts. Robust body structure.

💡 Technology Features

Infotainment Features:

Primarily AM/FM radio (optional cassette players available), analog gauges.

Driver Assistance Systems:

Optional cruise control. No electronic driver assistance systems (ABS, traction control, etc.) as understood today.

Connectivity Features:

No modern connectivity features like Bluetooth or USB. Original connectivity was limited to analog radio signals.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000-10,000 km (3,000-6,000 miles) or annually, depending on driving conditions and oil type used. Consult manual for precise intervals.

Tune Up Interval:

Points and condenser replacement, spark plug replacement, and ignition timing adjustment typically every 15,000-25,000 km (10,000-15,000 miles).

Engine Oil Type:

SAE 10W-30 or 10W-40 (API SE/SF or equivalent for gasoline engines); SAE 15W-40 or 20W-50 for diesel engines. Consult manual for exact viscosity and API ratings.

Coolant Type:

Ethylene glycol based antifreeze mixed with distilled water (50/50 ratio).

Transmission Fluid:

Manual: SAE 75W-90 or 80W-90 GL-4 gear oil. Automatic: Dexron II (or equivalent) for 722.X transmissions.

Common Wear Items:

Kingpins, ball joints, control arm bushings, vacuum lines (prone to cracking), fuel lines (rubber), exhaust system components, and carburetor diaphragm issues.

Common Diesel Issues:

Glow plug reliability, injection pump seals, and the tendency for early OM615/OM616 engines to be somewhat underpowered if not well-maintained.

📚 Vehicle History

Heritage:

Mercedes-Benz has a long-standing reputation for engineering excellence, safety, and longevity, which the W114/W115 series upheld.

Evolution Summary:

Introduced as the 'Neue Klasse' (New Class), it was a significant departure for Mercedes-Benz, aiming for a more modern and accessible luxury segment. It evolved through engine updates and minor styling tweaks during its production run.

Production Years:

1968-1976

Production Locations:

Germany (primarily Sindelfingen), with assembly plants in other countries as well.

🏆 Awards & Recognition

Historical Accolades:

While specific 'awards' are not commonly documented for individual vehicle models of this era, the W114/W115 series was widely praised for its engineering, durability, and comfort, contributing significantly to Mercedes-Benz's reputation for quality and luxury in the global market.