Body Styles Covered:
Limousine (W123), T-Limousine (S123), Coupe (C123)
Engine Variants Covered:
200, 200 D, 220 D, 230, 230 E, 240 D, 240 TD, 250, 250 D, 280, 280 E, 280 CE, 300 D, 300 TD
Chassis Codes:
W123 (Sedan), S123 (Estate/T-model), C123 (Coupe), V123 (Long Sedan), F123 (Chassis/Cab)
Production Years:
1976-1985
Positioning:
The Mercedes-Benz Typ-123 series (W123) was a range of executive automobiles produced by Mercedes-Benz from 1976 to 1985. It was designed as a successor to the W114/W115 and represented a significant evolution in Mercedes-Benz design and engineering, known for its robust construction, reliability, and comfort. This manual is essential for owners and mechanics maintaining these classic vehicles.
Competitors:
Competed against vehicles like the BMW 5 Series (E28), Audi 100 (C2), Volvo 240 Series, and certain Jaguar models of the era. The Typ-123 was often praised for its build quality and durability, setting a benchmark for its class.
Vehicle Highlights:
Exceptional build quality, legendary reliability, comfortable ride, spacious interiors, and a wide range of engine options (including the pioneering diesel engines for Mercedes-Benz in this class). The estate (T-model) version introduced practicality and versatility.
Value Proposition:
This manual is the definitive resource for maintaining, diagnosing, and repairing the Mercedes-Benz Typ-123. It mirrors the information used by official Mercedes-Benz dealerships, providing the highest level of detail and accuracy for DIY enthusiasts and professional workshops.
Mechanical:
Engine (Mechanical, Control System), Transmission (Manual, Automatic), Drive Shaft, Differential Case, Cylinder Head, Cylinder Block, Cooling System, Lubrication System, Fuel System, Exhaust System, Steering System, Suspension System (Front & Rear), Brake System
Electrical:
Charging System, Ignition System, Starting System, Lighting System, Combination Meter, Wiring Diagrams, Wiper & Washer System, Power Window Control System, Power Mirror Control System, Power Door Lock Control System
Bodywork:
Aufbau (Body Construction), Body Repair, Sun Roof System, Interior Trim, Exterior Trim
Comfort:
Klimatisierung (Air Conditioning), Heater Radiator
Maintenance:
Routine checks, fluid changes, filter replacements, lubrication
Repair:
Detailed step-by-step repair procedures for all major components
Diagnostics:
Troubleshooting guides for common problems, electrical system diagnostics
Overhaul:
Complete disassembly and reassembly instructions for engines, transmissions, etc.
Depth:
Comprehensive, covering everything from basic maintenance to complete rebuilds, suitable for DIY enthusiasts and professional mechanics alike.
Printability:
Fully printable, allowing users to print specific sections or the entire manual.
Paper Quality:
N/A (Digital)
Searchability:
Yes, fully searchable text allows for quick information retrieval.
Illustrations:
Detailed illustrations, drawings, and photos included.
Navigation:
Numbered table of contents for easy navigation.
Data Integrity:
100% complete and intact, no missing or corrupt pages/sections.
Engine Families:
M102 (4-cylinder petrol), M110 (6-cylinder petrol), OM615 (4-cylinder diesel), OM616 (4-cylinder diesel), OM617 (5-cylinder diesel)
Example 230E:
2.3L Inline-4, 136 hp (100 kW), 198 Nm torque (with Bosch K-Jetronic fuel injection)
Example 300Td:
3.0L Inline-5 Diesel, 88 hp (65 kW), 172 Nm torque
Petrol Injection:
Bosch K-Jetronic (CIS) on many models (e.g., 230E, 280E)
Diesel Injection:
Bosch inline injection pump
Type:
Pressurized liquid cooling system with fan (mechanical or viscous clutch type).
Oil Capacity:
Approximately 5-7 liters depending on engine (e.g., 6.5L for 230E).
Manual Gearbox:
4-speed and 5-speed manual transmissions were available.
Automatic Gearbox:
Optional 3-speed and 4-speed automatic transmissions (e.g., 722.1, 722.3).
Clutch System:
Hydraulically operated single dry plate clutch for manual transmissions.
Automatic Transmission Fluid:
Typically MB-Tex or Dexron II specification fluids (check manual for precise model year and type).
Example Sedan Length:
Approx. 4725 mm (W123 Sedan)
Example Coupe Length:
Approx. 4730 mm (C123 Coupe)
Example Estate Length:
Approx. 4760 mm (S123 T-Limousine)
Example Kerb Weight:
Approx. 1300-1500 kg depending on engine and body style.
Example Gross Vehicle Weight:
Approx. 1800-2000 kg
Crash Test Data:
While formal crash testing standards were less rigorous in the 1970s and 80s, the W123 was engineered with a strong safety cell, crumple zones, and robust construction, contributing to its reputation for occupant protection.
Brakes:
Front disc brakes and rear drum brakes (or disc brakes on later/higher-spec models). Optional ABS on later models.
Airbags:
Driver airbag became optional and then standard on some later models. Passenger airbags were not a common feature for this generation.
Seatbelts:
Front 3-point inertia-reel seatbelts, rear lap belts or 3-point belts depending on seating position and year.
Audio System:
Factory-fitted radios were typically AM/FM, often with cassette players on later models. Speaker placement varied by body style and trim.
Cruise Control:
Optional cruise control was available on some models.
Central Locking:
Vacuum-operated central locking system was a common feature, known for occasional vacuum line failures.
Air Conditioning:
Optional climate control or manual air conditioning systems were available.
Oil Change:
Typically every 10,000-15,000 km or annually, depending on driving conditions. Diesel engines may have slightly different intervals. Consult the manual for specifics.
Major Service:
Includes checks on cooling system, ignition timing, valve clearance, fuel system, and transmission service at intervals often ranging from 30,000 to 60,000 km.
Engine Oil Petrol:
API SF/SG or Mercedes-Benz specifications 229.1 or 229.3 (e.g., 10W-40, 15W-40, 5W-40 depending on climate). Check manual for exact grade.
Engine Oil Diesel:
API CD/CE or Mercedes-Benz specification 227.1 or 228.1 (e.g., 15W-40 diesel specific oil).
Coolant:
Mercedes-Benz approved coolant concentrate (e.g., G48 or similar ethylene glycol based) mixed with distilled water. Capacity approximately 8-10 liters.
Brake Fluid:
DOT 3 or DOT 4 glycol-based brake fluid.
Common Problems:
Rust (especially wheel arches, door bottoms, chassis), vacuum leaks affecting central locking and engine idle, overheating on older diesel models, worn front suspension components, potential for head gasket issues if overheated.
Preventive Measures:
Regular underbody washing and rustproofing, diligent maintenance of the cooling system, and monitoring of vacuum lines are key to longevity.
Mercedes Benz Legacy:
Mercedes-Benz has a long-standing reputation for engineering excellence, safety, and durability, built on a foundation of pioneering automotive innovation since the late 19th century.
Typ 123 Development:
The Typ-123 (W123) was developed to meet the growing demand for reliable, safe, and comfortable mid-size executive cars. It built upon the solid engineering principles of its predecessors, incorporating aerodynamic improvements and modern safety features for its time. The introduction of the T-model (estate) was a significant diversification for Mercedes-Benz.
Production Numbers:
Over 2.7 million units were produced across all body styles, making it one of Mercedes-Benz's most successful models of its era.
Manufacturing Locations:
Primarily manufactured in Germany, with some production also occurring in other global Mercedes-Benz plants.
