This manual covers the 300D models produced between 1976 and 1985, encompassing chassis codes W116 (1976-1980) and W123 (1977-1985). These vehicles, powered by the robust OM617 diesel engine in naturally aspirated and turbocharged variants, represent a significant era of engineering, known for their exceptional durability, comfort, and fuel efficiency. The 300D was positioned as a luxury or executive vehicle, competing with premium European marques of the time. This comprehensive guide acknowledges the heritage, particularly its pioneering role in diesel passenger vehicles, and highlights the 300D's unique appeal and longevity, making it a valuable resource for owners of these iconic sedans, coupes, and wagons.

This Factory Service Repair Workshop Manual provides detailed information for the maintenance, diagnosis, and repair of the 300D across its various iterations. It covers all major systems, including the powertrain, drivetrain, suspension, steering, brakes, electrical systems, and body/chassis components, along with HVAC systems. The manual includes essential procedures such as scheduled maintenance, troubleshooting common issues, component removal and installation, and detailed technical specifications. Its scope is global, offering in-depth guidance for owners and technicians to ensure the optimal performance and longevity of their vehicles.