🏷️ Basic Information

Make:

Mercedes-Benz

Model:

SL-Class

Chassis Code:

R107 / C107

Model Year Covered:

1974

👋 Introduction

Target Audience:

Owners and independent repair shops specializing in classic Mercedes-Benz vehicles.

Value Proposition:

Provides factory-level repair and maintenance information, enabling cost-effective vehicle care and preservation.

Comparison To Generic Manuals:

Offers significantly higher accuracy, detail, and completeness than generic aftermarket repair guides.

Feature 1:

Comprehensive A-Z repair coverage for all 1974 R107/C107 models.

Feature 2:

Includes factory diagrams, illustrations, and wiring schematics.

Feature 3:

Digital format offers portability and ease of use (print on demand).

Feature 4:

Eliminates the need for physical manual storage and potential damage.

📋 Manual Details

Primary Coverage:

Service and Repair

Secondary Coverage:

Maintenance, Diagnosis, Troubleshooting

Model Variants Covered:

All R107 and C107 SL-Class models for 1974

Estimated Page Count:

Varies by specific model/engine variant, but comprehensive.

Type:

Factory Service and Repair Manual

Language:

English

Digital Format:

PDF

Accessibility:

Windows Vista (32/64-bit), XP, ME, 98, NT, 2000, and Mac compatible.

📖 Manual Coverage

Engine:

Detailed information on maintenance, overhaul, and diagnosis of gasoline engines.

Control System:

Engine control systems, including fuel injection and ignition.

Mechanical:

Comprehensive mechanical system coverage including engine, chassis, and body.

Fuel System:

Fuel delivery, injection systems, carburetors (if applicable to '74 models), fuel pump, lines, and tank.

Emission Control:

Detailed procedures and specifications for emission control systems.

Cooling System:

Radiator, coolant, thermostat, water pump, and fan system service.

Lubrication System:

Oil pump, oil filter, lubrication specifications, and oil change procedures.

Ignition Starting Charging:

Battery, alternator, starter motor, ignition system components, and troubleshooting.

Transmission:

Automatic and Manual transmission service, repair, and overhaul.

Drivetrain:

Clutch, transfer case (if applicable), propeller shaft, drive shaft, and differential service.

Suspension Steering:

Front and rear suspension, steering column, power steering system, and alignment procedures.

Brakes:

Hydraulic brake system, brake control, parking brake, and disc/drum brake service.

Wheels Tires:

Wheel specifications, tire pressure, and mounting procedures.

Air Conditioning:

Service and repair of the climate control and air conditioning systems.

Electrical:

Complete electrical system diagnostics, wiring schematics, and component testing.

Body Interior Exterior:

Bodywork, doors, hood, glass, mirrors, seats, instrument panel, and interior trim.

Safety Systems:

Seat belts, supplemental restraint systems (if equipped), and related components.

Accessories:

Cruise control, windshield wipers and washers, horn, door locks, meters, audio/visual systems.

Maintenance:

Scheduled maintenance, fluid changes, filter replacements, tune-ups.

Repair:

Step-by-step instructions for all major and minor repairs.

Diagnosis:

Troubleshooting guides and diagnostic procedures for various systems.

Rebuilds:

Complete overhaul instructions for engines, transmissions, and major components.

Adjustments:

Detailed procedures for adjusting brakes, clutch, engine timing, and other systems.

Troubleshooting:

Systematic troubleshooting flowcharts and common problem resolutions.

Depth:

Factory-level detail, suitable for professional technicians and advanced DIY enthusiasts.

Accuracy:

Vehicle-specific and authoritative, not generic.

📊 Manual Specifications

Format:

PDF

Searchability:

Likely text-searchable PDF for quick information retrieval.

Printability:

All pages are printable, allowing users to print only necessary sections.

Image Scaling:

Ability to enlarge images and print them at a larger size.

Binding:

Digital (PDF), no physical binding.

Paper Type:

N/A (Digital Format)

Software Requirements:

Adobe PDF Reader and WinZip (or equivalent decompression software).

⚙️ Engine Specifications

Engine Options 1974 R107 C107:

Likely includes the M116 3.5L V8 and M117 4.5L V8 engines, depending on specific market and model.

Engine Block Material:

Aluminum Alloy (typical for these V8 engines)

Engine Configuration:

V8

Horsepower 3.5L:

Approx. 200-205 hp (SAE Gross, varies by market and tune)

Torque 3.5L:

Approx. 211-215 lb-ft (SAE Gross, varies by market and tune)

Horsepower 4.5L:

Approx. 220-230 hp (SAE Gross, varies by market and tune)

Torque 4.5L:

Approx. 270-280 lb-ft (SAE Gross, varies by market and tune)

Fuel Injection:

Bosch K-Jetronic (CIS) mechanical fuel injection for most models of this era.

Fuel Type:

Unleaded Gasoline (87 octane or higher, depending on market availability and engine tuning)

Oil Capacity V8:

Approximately 8 US quarts (7.5 Liters) with filter change. Specific capacity will be detailed in manual.

Recommended Oil Viscosity:

Likely 20W-50 or 10W-40, depending on climate. Manual will specify exact grades and API service classifications.

🔧 Transmission

Transmission Options:

Automatic transmission (e.g., 3-speed or 4-speed automatic) was standard or widely available. Manual transmission might have been an option in some markets.

Manual Transmission Availability:

Possible availability of a 4-speed or 5-speed manual transmission depending on market and specific model designation.

Automatic Transmission Type:

Typically a robust Torque Converter Automatic (e.g., 3HP20 or similar predecessor/variant).

Automatic Transmission Fluid Type:

Likely a DEXRON II or equivalent fluid. Manual will specify exact Mercedes-Benz fluid specification (e.g., MB 236.2).

Transmission Fluid Capacity:

Approx. 8-10 US quarts (7.5-9.5 Liters) for automatic transmission with torque converter. Manual will confirm.

📐 Dimensions

Body Style:

2-door Convertible with removable hardtop (Roadster / SL) and potentially a 2-door Coupe variant (SLC).

Wheelbase:

Approx. 96.7 inches (2455 mm) for R107; Approx. 107.1 inches (2720 mm) for C107.

Curb Weight:

Approx. 3500 - 3800 lbs (1588 - 1724 kg), varies by engine and options.

🛡️ Safety Features

Safety Ratings:

N/A - Crash testing standards were less rigorous and standardized in 1974. Manual may reference internal Mercedes-Benz testing.

Active Safety Features:

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

Passive Safety Features:

Reinforced A-pillars (in convertible design), collapsible steering column, safety glass, inertia-reel seat belts.

💡 Technology Features

Infotainment System:

Basic analog radio and cassette player were common. Manual may cover installation/removal of these components and speakers.

Driver Assistance Features:

Limited by 1974 standards; primarily focused on the mechanical systems for safety and driver control.

Connectivity Features:

N/A (no electronic connectivity features as understood today).

Wiring Schematics Detail:

Comprehensive, clear wiring diagrams are a key feature, essential for diagnosing electrical faults.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-6,000 miles or 6-12 months, depending on usage and oil type. Manual will specify.

Transmission Service Interval:

Fluid and filter change usually recommended every 30,000-50,000 miles. Manual will provide precise interval.

Tune Up Interval:

Spark plugs, ignition components, and fuel system checks typically every 15,000-30,000 miles. Manual will detail.

Coolant Type:

Ethylene Glycol based antifreeze. Manual will specify Mercedes-Benz coolant specification.

Brake Fluid Type:

DOT 3 or DOT 4 brake fluid. Manual will specify the exact Mercedes-Benz approved fluid.

Common Issues R107 C107:

Rust (especially around wheel arches, sills, and convertible top frame), vacuum hose degradation affecting climate control and central locking, cooling system leaks, potential timing chain wear (on higher mileage V8s), fuel distributor issues with K-Jetronic.

📚 Vehicle History

Brand Description:

Mercedes-Benz has a long-standing reputation for engineering excellence, luxury, and durability.

R107 C107 Lineage:

The R107/C107 platform succeeded the iconic W113 'Pagoda' SL and was in production for a significant period (1971-1989 for R107, 1972-1981 for C107), making it one of the longest-produced Mercedes-Benz chassis.

Production Period R107 C107:

1971-1989 (R107), 1972-1981 (C107)

Key Design Innovations:

Robust body structure, independent rear suspension, sophisticated V8 engines (for many variants), and iconic convertible styling.

🏆 Awards & Recognition

Industry Recognition:

While specific awards for the '74 model year might be scarce, the R107/C107 platform is widely recognized for its build quality, luxury, and longevity, becoming a classic automotive icon.