YB00001775 Original Excavator Hydraulic Main Pump Housing Gear for ZX330-5G

The part number YB00001775 is the original hydraulic main pump housing internal gear provided by Hitachi for the ZX330-5G hydraulic excavator. This gear is the core component of the main pump transmission system, which is matched with gear YB00001775 to form a complete original power unit. Its universal model is strictly limited to ZX330-5G and 5G series same platform models such as ZX350-5G and ZX370-5G that use the same main pump. It is strictly prohibited to use this gear for other series of pump bodies to avoid abnormal wear or pump body scrapping due to inconsistent meshing parameters.

This product is a helical gear or planetary gear installed inside the main pump housing. The gears are made of high-strength alloy steel, which has been treated with carburizing quenching and precision grinding technology. The tooth surface hardness is high, reaching HRC 58-62, ensuring smooth transmission and withstanding huge torque under high pressure and high speed. Its module, number of teeth, helix angle, and another gear inside the housing form a precision meshing pair, which is a key conversion link for the power of the pump unit.

Inspection and maintenance: The cleanliness of hydraulic oil should be checked every 1000 working hours. Oil contamination is the main cause of abnormal gear wear. Fault diagnosis: If there is abnormal noise or unstable output in the main pump, after ruling out other causes, it is necessary to dismantle and inspect whether there is pitting, peeling or excessive meshing clearance on the tooth surface of this gear pair. Timing of replacement: Once irreparable damage is found on the tooth surface, the meshing gears must be replaced in pairs and the bearings must be checked synchronously. Be sure to use this original gear (YB00001775)