This manual covers the Komatsu WA800-3E0 and WA900-3E0 wheel loaders, designed for demanding industrial and construction applications. These machines are engineered for robust performance, reliability, and efficiency in heavy-duty operations. The comprehensive documentation provided ensures users can maximize the potential of their equipment through proper operation and maintenance. This document serves as a complete Service Repair Manual, Field Assembly Instruction, and Operation & Maintenance Manual. It details specifications, structure, function, maintenance standards, testing, adjusting, troubleshooting, and disassembly/assembly procedures. Additionally, it includes operational guidance for peak performance, safety protocols, and maintenance schedules, enabling owners and technicians to effectively service, repair, and operate these wheel loaders.