Vehicle Segment:
Mid-size luxury sedan and wagon, known for its robust build quality, diesel efficiency, and enduring appeal.
Key Competitors:
BMW 5 Series Diesel, Audi 100 Diesel, Volvo Diesel models of the era.
Vehicle Strengths:
Legendary Mercedes-Benz diesel reliability, fuel economy, comfortable ride, solid construction, and timeless design.
Target Audience:
Enthusiasts, DIY mechanics, and professional workshops specializing in classic Mercedes-Benz vehicles.
Manual Coverage Scope:
Comprehensive repair, service, and maintenance for Mercedes-Benz W123 300 D Turbo models with specified engine variants.
Estimated Page Count:
Likely 1000+ pages (typical for comprehensive factory-level manuals for this era).
Manual Classification:
Factory Service Manual / Workshop Manual / Repair Manual
Manual Language:
English (assumed, common for such manuals).
Digital Format:
PDF (Downloadable)
Powertrain:
Engine (OM615, OM617, OM617 A, M115 - including diesel injection systems, turbocharging), Transmission (manual and automatic), Drivetrain (driveshafts, differentials).
Chassis And Suspension:
Front and rear suspension, steering system, brakes (hydraulic and parking brake), wheels and tires.
Electrical And Electronics:
Engine control unit (where applicable), lighting systems, instrumentation, starter, charging system, wiring diagrams, comfort systems.
Body And Interior:
Body panels, doors, glass, upholstery, HVAC (heating, ventilation, and air conditioning).
Maintenance Procedures:
Routine servicing, fluid changes, filter replacements, lubrication, belt adjustments.
Repair Procedures:
Detailed step-by-step instructions for component removal, installation, and overhaul (engine rebuilds, transmission overhauls, brake caliper replacement, etc.).
Troubleshooting:
Diagnostic charts, fault finding procedures, common problem identification and solutions.
Special Tools And Equipment:
Identification and usage of specialized tools required for specific repair tasks.
Diagnostic Capabilities:
Advanced diagnostics, including fuel system pressures, compression testing, and electrical circuit analysis.
Rebuild Specifications:
Complete engine and transmission rebuild specifications, including clearances, tolerances, and torque values.
Electrical Schematics:
Detailed and accurate wiring diagrams for all vehicle systems.
Digital File Quality:
High-resolution scans, typically searchable text for ease of navigation and information retrieval.
Print Suitability:
Designed for clarity, with diagrams and schematics easily printable for workshop use.
Original Binding:
Typically spiral-bound or perfect-bound for durability in a workshop environment.
Original Paper Quality:
Heavy-duty, durable paper stock to withstand frequent use in a garage.
Engine Type:
Inline-5 Cylinder Diesel (OM617) and OM617 A (Turbocharged), and Inline-4 Cylinder Diesel (OM615).
Displacement Om617:
3.0 Liters (2998 cc)
Displacement Om615:
2.4 Liters (2404 cc)
Horsepower Om617 Naturally Aspirated:
Approximately 80-85 hp
Horsepower Om617 Turbocharged:
Approximately 125 hp
Torque Om617 Turbocharged:
Approximately 250 Nm (184 lb-ft)
Fuel Injection:
Bosch inline injection pump with mechanical injectors.
Bore Stroke Om617:
91 mm x 92.4 mm
Compression Ratio Om617:
21.0:1
Standard Transmission Type:
4-speed manual transmission.
Optional Transmission Type:
4-speed or 5-speed automatic transmission (e.g., 4G-TRONIC).
Automatic Transmission Mode:
Comfort and Economy modes often selectable on automatic transmissions.
Automatic Transmission Fluid Spec:
MB specification (e.g., ATF Dexron II or equivalent).
Crash Safety Era:
Designed to contemporary safety standards of the late 1970s and early 1980s.
Braking System:
Front disc brakes, rear drum brakes. Later models and some variants may have rear discs.
Occupant Protection:
Reinforced passenger cell, crumple zones, padded dashboard, seat belts (front and often rear).
Oil Change Interval:
Typically 5,000-7,500 miles (8,000-12,000 km) or 6-12 months, depending on usage.
Fuel Filter Replacement:
Approximately 15,000-20,000 miles (24,000-32,000 km).
Air Filter Replacement:
Approximately 10,000-15,000 miles (16,000-24,000 km).
Engine Oil Type:
Diesel Engine Oil, e.g., SAE 10W-40 or 15W-40 API CD/CE rated (consult manual for specific grades).
Engine Oil Capacity:
Approximately 6.5 - 7.5 liters (with filter).
Coolant Type:
Ethylene glycol-based antifreeze mixed with distilled water (50/50).
Diesel Engine Longevity:
OM617 engines are known for exceptional longevity if properly maintained; common issues can include glow plug reliability, vacuum leaks, and injector pump maintenance.
Rust And Corrosion:
A common issue for W123 models, particularly around wheel arches, door bottoms, and battery trays.
Suspension Wear:
Bushings and ball joints can wear over time, leading to steering looseness and noise.
Climate Control System:
Older HVAC systems may require refrigerant recharge or component replacement (e.g., compressor, drier).
Mercedes Benz Legacy:
Renowned for engineering excellence, luxury, safety, and durability since the late 19th century.
W123 Introduction:
Introduced in 1976, succeeding the W114/W115 series. The 300 D Turbo variant (OM617 A) was a significant addition, offering enhanced performance.
Production Years:
1976-1985 (W123 chassis).
Manufacturing Locations:
Primarily Sindelfingen, West Germany, with global assembly plants.
Historical Reputation:
The W123 series is widely regarded as one of the most reliable and well-built Mercedes-Benz models ever produced, often cited in 'best used car' lists for durability.
Consumer Reports Historical:
Consistently rated highly for reliability and owner satisfaction in period and subsequent reviews of classic cars.
