This manual covers the 1991 Mercedes-Benz 350 SD Turbo, a full-size luxury sedan from the W140 chassis generation. This model is distinguished by its robust build quality, emphasis on comfort and advanced technology for its era, and the inclusion of a powerful and efficient 3.5-liter turbocharged inline-six diesel engine (OM603.970). As a flagship offering, it competed with other premium sedans of the time, providing a blend of luxury, performance, and the renowned engineering excellence associated with the Mercedes-Benz brand.

This comprehensive workshop manual provides detailed information for the maintenance, repair, and diagnostics of your 1991 Mercedes-Benz 350 SD Turbo. It covers all major systems, including the OM603.970 diesel engine, the 4-speed automatic transmission, drivetrain, suspension, brakes, steering, and the electrical system. With over 1000 pages of content, this manual offers in-depth procedures for component removal and installation, troubleshooting common issues, and performing routine maintenance, empowering owners and technicians to keep the vehicle in optimal condition.