Target Audience:
Mechanical Technicians, Experienced DIY Mechanics
Advantage:
Provides comprehensive coverage akin to authorized dealer service departments, emphasizing proprietary component repair.
Safety Emphasis:
Includes warnings, cautions, and notes regarding safety procedures and the use of safety equipment (e.g., torque wrench).
Diagnostic Aid:
Offers diagnostic and repair procedures for troubleshooting issues.
Cost Saving:
Enables owners to perform maintenance and repairs, saving on labor and overhead costs.
Covered Years:
1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Type:
Workshop Service Manual / Repair Manual
Engine Systems:
Fuel System, Ignition System, Lubrication System, Cooling System, Engine Mechanical (Disassembly/Reassembly), Emission Control
Drivetrain Systems:
Transmission (Manual & Automatic), Driveshaft, Differential, Axles
Chassis Systems:
Suspension (Front & Rear), Steering System, Brake System (Hydraulic & Parking), Wheels & Tires
Electrical Systems:
Electrical System Overview, Wiring Diagrams, Lighting, Instruments & Gauges, Starting & Charging System, Ignition System, Power Accessories
Body Systems:
Body Construction, Doors, Hood, Trunk, Windows, Seats, Interior Trim, Body Repairs
Maintenance Procedures:
Routine Maintenance, Tune-Ups, Fluid Changes, Filter Replacements, Inspection Procedures
Repair Procedures:
Component Removal and Installation, Overhaul Procedures, Engine Rebuild, Transmission Repair, Brake System Servicing, Electrical Component Repair
Diagnostic Procedures:
Troubleshooting Guides, Symptom-Based Diagnostics, Component Testing Procedures
Special Procedures:
Proprietary Component Repair Instructions, Use of Special Tools
Depth:
Comprehensive (from routine maintenance to full engine/transmission overhaul)
Engine Type:
Inline 6-Cylinder (M110 engine family)
Displacement:
2.8 Liters (2780 cc)
Horsepower Range:
Approx. 138-145 hp (gross), dependent on specific model year and emissions equipment.
Torque Range:
Approx. 220-230 Nm (approx. 162-170 lb-ft) gross.
Fuel Delivery:
Bosch K-Jetronic (CIS) Continuous Injection System
Fuel Type:
Unleaded Gasoline (Octane rating as specified by Mercedes-Benz)
Ignition Type:
Electronic Ignition (typically with distributor and ignition coil)
Cooling Medium:
Water/Antifreeze mixture
Oil Capacity:
Approx. 6.5 - 7.0 Liters (7.0 - 7.4 US Quarts) with filter change. Specific capacity detailed in manual.
Type:
4-Speed Manual Transmission (optional early in production, replaced by automatics as primary)
Type:
4-Speed Automatic Transmission (722.1, 722.3 series)
Automatic Features:
Torque converter lock-up (depending on model year and specific transmission variant)
Automatic Transmission Fluid:
MB-Approval 236.2 (Dexron-II equivalent, e.g., Shell Donax TX or equivalent specified).
Manual Transmission Fluid:
SAE 80W-90 GL-4 or GL-5 gear oil.
Length:
Approx. 4725 mm (186.0 in)
Width:
Approx. 1790 mm (70.5 in)
Height:
Approx. 1425 mm (56.1 in)
Curb Weight:
Approx. 1400-1500 kg (3086-3307 lbs), varies by equipment.
Gross Vehicle Weight Rating:
Typically around 1900-2000 kg.
Wheelbase:
Approx. 2795 mm (110.0 in)
Crash Safety:
Designed to meet safety standards of its era; modern independent crash test data is limited but known for robust build quality.
Braking System:
Four-wheel disc brakes (ventilated front discs) with hydraulic assist.
Construction:
Reinforced passenger cell, energy-absorbing steering column, safety glass.
Seat Belts:
Standard three-point front seat belts, lap belts in rear.
Oil Change Interval:
Typically every 10,000-15,000 km (6,000-9,000 miles) or annually. Refer to specific manual for exact intervals.
Air Filter Replacement:
Recommended every 20,000-30,000 km (12,000-18,000 miles) or as needed based on conditions.
Spark Plug Replacement:
Refer to manual; typically around 30,000-40,000 km for conventional plugs.
Transmission Fluid Change:
Automatic: Every 50,000-80,000 km (30,000-50,000 miles). Manual: Check condition, usually less frequent. Manual specifies intervals.
Engine Oil Specification:
API SG or higher, SAE 15W-40 or 10W-40 recommended. Check manual for specific viscosity based on ambient temperature.
Coolant Type:
Ethylene glycol based antifreeze with corrosion inhibitors (e.g., Mercedes-Benz Spec 325.0 or equivalent).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Common Wear Items:
Ball joints, tie rod ends, wheel bearings, fuel distributor seals (K-Jetronic), vacuum lines, and climate control actuators can be common wear items over time.
Rust Prone Areas:
Wheel arches, sills, door bottoms, and trunk floor are susceptible to rust, especially in certain climates.
K Jetronic Issues:
Fuel distributor, airflow meter, and auxiliary air regulator issues can lead to rough idling, stalling, or poor performance.
Manufacturer Reputation:
Mercedes-Benz is globally renowned for engineering excellence, build quality, durability, and technological innovation in luxury and commercial vehicles.
W123 Series Positioning:
The W123 chassis represented Mercedes-Benz's mid-size executive sedan and estate range, known for its robust engineering, reliability, and comfortable ride. It was a highly successful and influential model for the brand.
280E Variant:
The 280E was a higher-performance variant, featuring the smooth and potent M110 inline-six engine, typically equipped with fuel injection for better power and efficiency compared to carbureted models.
Production Location:
Primarily manufactured in Germany.
Sales Volume:
The W123 series was produced in large numbers, selling over 2.7 million units worldwide, underscoring its popularity and success.
