CANON - Canon EF 400mm f56L USM Parts

Complete parts catalog for the Canon EF 400mm f/5.6L USM telephoto lens (reference C21-8362). This professional workshop manual serves as an essential reference for service technicians, authorized Canon repair centers, and optical maintenance specialists. The catalog features detailed exploded-view diagrams showing the complete mechanical and optical assembly—from lens groups through to the camera mount interface. Every component carries its specific Canon part number, enabling technicians to identify and order replacement parts with precision during repair or overhaul work. The comprehensive parts list provides original Canon reference numbers for each component, along with classifications, quantities, detailed descriptions, and page references for cross-referencing. Diagrams systematically cover all major assemblies: the optical mount, lens group arrangement (G1 through G7), motorized diaphragm mechanism, focusing unit assembly, mechanical locking elements, focus ring and distance scale ring, plus external accessories including the lens hood and rear protective cap. Dimensional specifications for key optical elements support proper reassembly and alignment. Component references clearly distinguish between earlier and later production versions, allowing technicians to verify compatibility and source the correct replacement for the specific lens variant being serviced.