Hitachi 4325230 Pump Coupling Assembly

The Hitachi 4325230 pump coupling element is a Centaflex-type rubber flexible coupling designed for hydraulic pump drive applications on Hitachi EX55UR and EX58MU mini excavators. It serves as the critical connection between the hydraulic pump input shaft and the engine flywheel, transmitting engine torque to the main hydraulic pump while damping torsional vibrations and accommodating misalignment. Constructed with a rubber elastic element bonded to metal hubs, the coupling provides excellent resistance to heat, oil, and low-temperature environments typical of construction machinery operation. The flexible rubber element absorbs shock loads and reduces vibration transmission between the engine and hydraulic pump, extending component service life. This coupling is a direct replacement for Hitachi OEM part number 4325230 and cross-references to part numbers 4310056, 4101345, 4334891, and 4393115.