Segment:
Luxury Grand Tourer Convertible
Target Audience:
Owners, independent repair shops, Mercedes-Benz enthusiasts seeking in-depth knowledge.
Competitors:
BMW 8 Series (E31), Jaguar XJS, Porsche 928.
Vehicle Highlights:
Powerful V8 engine, sophisticated suspension, iconic styling, advanced (for its era) safety and comfort features, hallmark Mercedes-Benz build quality.
Utility:
Essential for maintaining the complex systems of the R129 SL, enabling DIY repairs and informed professional service.
Engine:
Diagnosis, removal, installation, overhaul, lubrication, cooling, fuel injection (KE-Jetronic), ignition, exhaust.
Transmission:
Diagnosis, removal, installation, overhaul, fluid specifications for 4-speed Automatic (722.3/722.4).
Chassis:
Suspension (front/rear), steering, brakes (hydraulic, ABS), wheels, tires.
Electrical:
Wiring diagrams, starter, alternator, battery, lighting, instruments, power windows, mirrors, seats, convertible top mechanism, climate control, audio system, electronic control modules (ECU).
Body:
Body structure, exterior trim, interior trim, doors, hood, trunk, convertible top.
Maintenance:
Scheduled maintenance, fluid changes, filter replacements, tune-ups.
Diagnostics:
Troubleshooting guides, symptom-based diagnosis, diagnostic trouble codes (DTCs) where applicable (OBD-I era).
Repair:
Component disassembly, inspection, repair, assembly, and installation procedures.
Specifications:
Torque specifications, clearances, fluid capacities, electrical specifications.
Depth:
Comprehensive: Covers everything from basic maintenance to complete engine and transmission overhauls, complex electrical system diagnosis, and convertible top mechanism repair.
Engine Type:
V8, Naturally Aspirated
Displacement:
4973 cc (5.0 Liters)
Bore X Stroke:
96.5 mm x 85.0 mm
Compression Ratio:
10.0:1
Horsepower Hp:
322 hp @ 5500 rpm (approx.)
Torque Lb-Ft:
354 lb-ft @ 3750 rpm (approx.)
Fuel Delivery:
Bosch KE-Jetronic (CIS-E) Electronic Fuel Injection
Fuel Type:
Premium Unleaded Gasoline (91+ Octane)
Type:
Electronic Ignition
Type:
Water Cooled, Thermostatically Controlled
Type:
4-Speed Automatic Transmission
Transmission Codes:
722.3xx / 722.4xx
Electronic Control:
Yes (for shift points and lock-up)
Fluid Type:
MB Spec 236.1 (e.g., Mobil ATF 220, Dexron III compatible)
Capacity Quarts:
Approx. 8-9 Quarts (dry fill), 6 Quarts (service fill)
NHTSA Ratings:
N/A (Pre-mandatory rating era, but designed to high standards)
ABS:
Standard (Bosch ABS II)
Traction Control:
Optional (ASR - Acceleration Slip Regulation on later models)
Airbags:
Driver's side airbag (standard), passenger airbag (optional/later models)
Rollover Protection:
Automatic rollover protection system (pop-up roll bar activated by sensors)
Seatbelts:
Integrated seatbelts, pretensioners
Audio System:
Factory premium sound system (e.g., Becker, Bose optional).
Climate Control:
Automatic climate control with cabin air filter.
Memory Seats:
Optional (driver and passenger)
Bluetooth:
Not available from factory.
Operation:
Hydraulic power-operated soft top with integrated hardtop availability.
Oil Change Interval Miles:
Typically 7,500 - 10,000 miles or annually, depending on driving conditions.
Transmission Fluid Interval Miles:
Recommended every 30,000-50,000 miles for optimal performance.
Coolant Flush Interval Miles:
Every 2-3 years or 30,000-50,000 miles.
Engine Oil Spec:
MB 229.1 (e.g., 15W-40 or 10W-40 synthetic blend, check specific manual for temperature grades).
Engine Oil Capacity Quarts:
Approx. 8.0 Quarts (with filter)
Power Steering Fluid Spec:
MB Spec 236.3 (e.g., Pentosin CHF 11S)
Wiring Harness Degradation:
Cracking and insulation breakdown in older wiring harnesses, especially engine bay components.
Hydraulic System Leaks:
Leaks in the suspension leveling system or convertible top hydraulic lines.
Engine Mounts:
Degradation leading to increased vibration.
Seat Belt Retractor:
Malfunctions in the automatic seat belt presenter/retractor system.
Ignition Coil Failure:
Premature failure of ignition coils.
Mercedes Benz Legacy:
Renowned for engineering excellence, durability, and luxury vehicles since the late 19th century.
R129 Introduction:
Introduced in 1989 as the successor to the R107 SL. Represented a significant modernization and technological leap.
R129 Lifespan:
Produced from 1989 to 2001.
Manufacturing Location:
Sindelfingen, Germany
R129 500Sl Production Years:
1989-1993 (pre-facelift)
