🏷️ Basic Information

Make:

Mercedes-Benz

Model:

SL-Class

Model Code:

R129

Year:

1998

Generation:

Third Generation (R129)

👋 Introduction

Segment:

Luxury Grand Tourer Convertible

Target Audience:

Owners seeking to perform their own maintenance and repairs, independent repair shops, enthusiasts.

Comparison:

Competed with luxury convertibles like the BMW 8 Series convertible, Jaguar XJS, and Porsche 911 Targa during its production run.

Distinction:

Known for its robust build quality, advanced safety features for its era, sophisticated engineering, and luxurious appointments.

Manual Advantage:

Provides dealership-level technical accuracy and detail, enabling DIY repairs with confidence.

📋 Manual Details

Primary Coverage:

Service, maintenance, diagnosis, and repair

Scope:

All models and all repairs A-Z

Estimated Page Count:

Extensive (detailed technical manuals typically range from 1000+ pages)

Type:

Factory Authorized Service and Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Powertrain:

Engine mechanicals, fuel system, cooling system, lubrication, exhaust system, ignition system, starting and charging system, automatic transmission, manual transmission (if applicable to specific variants), differential, drive shafts, axles.

Chassis:

Suspension (front and rear), steering system (including power steering), brake system (hydraulic, ABS, parking brake), wheels and tires.

Electrical:

Complete wiring schematics, lighting, instrumentation, power windows, locks, mirrors, seats, climate control, supplemental restraint system (SRS), cruise control, windshield wipers and washers, audio/visual systems, horn, engine immobilizer, multiplex/CAN communication.

Body:

Body exterior and interior components, doors, hood, glass, mirrors, seats, instrument panel.

Maintenance:

Scheduled maintenance, fluid changes, filter replacements, inspections.

Diagnostics:

Troubleshooting guides, symptom-based diagnostics, electrical system diagnostics, engine performance diagnostics.

Repair:

Step-by-step repair instructions for all major components and systems, including disassembly, reassembly, adjustments, and specifications.

Specifications:

Torque specifications, fluid capacities and types, technical data, clearances, timing settings, diagnostic trouble codes (DTCs).

Depth:

Factory-level, detailed step-by-step instructions, diagrams, illustrations, and wiring schematics for complete repair.

📊 Manual Specifications

File Type:

PDF

Searchability:

Searchable text content

Printability:

All pages printable, ability to enlarge images for printing.

Binding:

Digital (PDF)

Paper Type:

N/A (Digital format)

Operating Systems:

Windows (Vista 32/64, XP, ME, 98, NT, 2000) and Mac OS

Software Requirements:

Adobe PDF Reader, Winzip (both free online)

⚙️ Engine Specifications

Engine Options 1998:

For 1998, the R129 SL-Class primarily offered the SL500 with the M119 V8 engine and potentially the SL600 with the M120 V12 engine.

Engine Code Sl500:

M119 (e.g., M119 E50 DE LA)

Engine Displacement Sl500:

5.0 Liters (4973 cc)

Engine Configuration Sl500:

60-degree V8

Engine Performance Sl500 Approx:

Approx. 322 hp @ 5500 rpm, 339 lb-ft @ 3900 rpm

Engine Code Sl600:

M120

Engine Displacement Sl600:

6.0 Liters (5987 cc)

Engine Configuration Sl600:

60-degree V12

Engine Performance Sl600 Approx:

Approx. 389 hp @ 5200 rpm, 420 lb-ft @ 3800 rpm

Fuel Delivery:

Bosch Motronic Electronic Fuel Injection (EFI)

Fuel Type:

Premium Unleaded Gasoline (91 octane or higher)

🔧 Transmission

Transmission Sl500:

4-speed automatic transmission (722.6 '5G-Tronic' introduced in later years, but 1998 likely had the 722.3 or 722.4)

Transmission Sl600:

4-speed automatic transmission (722.6 '5G-Tronic')

Manual Transmission Availability:

Not typically offered on R129 SL-Class models.

Electronic Control:

Electronically controlled transmission with multiple shift modes (e.g., Economy/Sport on some variants).

📐 Dimensions

Length:

Approx. 187.7 inches (4768 mm)

Width:

Approx. 70.2 inches (1783 mm)

Height:

Approx. 51.2 inches (1300 mm)

Wheelbase:

Approx. 101.8 inches (2586 mm)

Curb Weight Sl500 Approx:

Approx. 3,900 lbs (1769 kg)

Curb Weight Sl600 Approx:

Approx. 4,300 lbs (1950 kg)

🛡️ Safety Features

Safety Standards:

Built to meet or exceed contemporary European and US safety standards.

ABS:

Standard Anti-lock Braking System (ABS)

Traction Control:

Optional or standard Acceleration Slip Regulation (ASR) depending on market and specific model.

Airbags:

Driver and passenger airbags.

Rollover Protection:

Automatic pop-up roll bar system integrated behind the headrests, deployed by sensors in case of a detected rollover.

Seat Belts:

Pretensioning seatbelts.

💡 Technology Features

Audio System:

Factory premium audio system, often with cassette player and optional CD changer. Radio functions controlled via buttons on the center console and/or steering wheel.

Climate Control:

Automatic climate control with dual-zone temperature settings.

Cruise Control:

Standard electronic cruise control.

Connectivity Features:

Limited by 1998 standards. Typically no integrated Bluetooth or Wi-Fi. Aftermarket solutions may be available.

Multiplex Communication:

The manual covers multiplex communication systems, indicating a degree of electronic integration for various vehicle functions.

🔧 Maintenance

Oil Change Interval:

Typically every 7,500 - 10,000 miles or 12 months, depending on driving conditions. Consult manual for specific intervals.

Major Service Interval:

Major services often around 30,000, 60,000, 90,000 miles including transmission fluid, coolant, spark plugs, etc. Consult manual for exact mileages.

Engine Oil Type:

Synthetic engine oil, typically meeting Mercedes-Benz MB-Approval 229.1 or 229.3 specification. Viscosity grade such as 0W-40 or 5W-40 is common.

Coolant Type:

Ethylene Glycol based coolant, typically meeting Mercedes-Benz specification 325.0 or 326.0 (often a green or blue color).

Transmission Fluid:

Automatic Transmission Fluid (ATF) meeting Mercedes-Benz specification 236.x (e.g., MB 236.8 for older 4-speeds, or MB 236.10/236.12 for 5-speed 722.6).

Brake Fluid Type:

DOT 4 approved brake fluid.

Wiring Harness Issues:

Known issues with biodegradable insulation on certain wiring harnesses, leading to degradation and electrical problems. Early detection and replacement is crucial.

Hydraulic System Failures:

Potential issues with the hydraulic system for the convertible top and roll bar, which can be complex to diagnose and repair. Leaks are also possible.

தகि Components:

Wear and tear on suspension components (e.g., ball joints, bushings) due to the vehicle's weight and performance capabilities.

Crankshaft Position Sensor:

Failure of the crankshaft position sensor (CKP) can lead to stalling or no-start conditions, particularly on V8 and V12 engines.

Mass Air Flow Sensor:

Dirty or failing Mass Air Flow (MAF) sensor can cause engine performance issues, hesitations, and rough idling.

📚 Vehicle History

Heritage:

Mercedes-Benz has a long-standing reputation for building high-quality, luxurious, and technologically advanced vehicles, particularly in the grand touring and convertible segments.

R129 Introduction:

The R129 SL-Class was introduced in 1989 as a successor to the R107 SL, offering a more aerodynamic design and significantly advanced technology.

R129 Updates 1998:

The 1998 model year represents a facelifted version of the R129, with updates to styling (e.g., front bumper, clear turn signals), interior, and potentially powertrain revisions. The 5-speed automatic transmission (722.6) became more prevalent.

Production Period:

1989–2001

Manufacturing Location:

Germany

🏆 Awards & Recognition

Brand Reputation:

Mercedes-Benz vehicles, including the SL-Class, consistently receive recognition for engineering excellence, luxury, and reliability.

Specific Awards 1998 Sl Class:

While specific awards for the 1998 model year may vary, the R129 generation generally received praise in automotive press for its performance, safety, and luxury credentials.

Manufacturing Standards:

Produced under strict ISO quality management standards.