The Mercedes-Benz 300D, chassis code W123, represents a significant era in automotive engineering, produced from 1976 to 1985. This mid-size luxury sedan, powered by the robust OM617 naturally aspirated inline 5-cylinder diesel engine, is renowned for its exceptional build quality, durability, and fuel efficiency. Its reputation as one of Mercedes-Benz's most reliable models, often nicknamed "the tank," underscores its engineering prowess and enduring appeal. The 300D offers a comfortable ride and a timeless design, making it a sought-after vehicle for those who appreciate classic automotive values and long-term dependability.

This comprehensive service and repair manual provides essential guidance for owners and technicians alike. It covers all major systems and components of the Mercedes-Benz 300D (W123), including detailed procedures for engine diagnosis and repair, fuel system maintenance, transmission overhaul, drivetrain, suspension, steering, brakes, and the electrical system. With expert-level detail, step-by-step instructions, troubleshooting guides, and precise technical specifications, this manual is an indispensable resource for performing routine maintenance, complex repairs, and ensuring the continued longevity and optimal performance of your 300D.