This manual covers the Mercury MerCruiser MerCruiser #27 Marine Engines V-8 Diesel D7.3L D-Tronic, produced between 1998 and 2002. These robust marine engines are engineered for reliability and performance, featuring a 7.3-liter V-8 diesel configuration with turbocharging and D-Tronic electronic control. Designed for marine sterndrive applications, they are compatible with various sterndrive models including MR/Alpha One/Alpha One SS, I-R, and Alpha One Counter Rotation. The engines also incorporate power trim systems and offer both power and manual steering options, making them a versatile choice for a range of maritime needs. This comprehensive Service Repair Manual, written in English, provides detailed, illustrated, step-by-step instructions for the maintenance, troubleshooting, repair, and rebuilding of your Mercury MerCruiser engine. Covering essential areas such as routine maintenance, corrosion protection, and specific system diagnostics for power trim and steering, this manual is an indispensable resource for professional technicians, mechanics, workshops, and DIY enthusiasts. Its extensive content, spanning 631 pages, includes zoomable illustrations, detailed component explosions, and exploded views, ensuring a thorough understanding and effective execution of all service procedures.