4487780 Excavator Bushing for EX1900-6

Part number 4487780 is a genuine liner produced by Hitachi Construction Machinery Co., Ltd. in Japan. Specially designed for the support chain (rail link) system of crawler excavators, it serves as a wear-resistant shaft sleeve for hinge points such as chain links, supporting wheels, or guide wheels. Therefore, it is mainly suitable for the Hitachi EX1900-6 ultra large mining hydraulic excavator and is also applicable to large models of the same series with the same support chain structure (such as EX1800-6).

This product is a cylindrical wear-resistant liner made of high-strength alloy steel precision machining. It is a standard silver gray metal cylinder with a surface treated with phosphating or similar anti rust treatment, and comes with an axial oil groove for storing and distributing lubricating grease. Its core function is to be installed in the hinge holes of the support chain, serving as a wear-resistant medium between the pin shaft and the link plate (or other connecting parts), reducing direct friction between metals, absorbing impact, and extending the service life of the pin shaft and link through its excellent wear resistance.

Inspection cycle: Add lubricating grease to each lubrication point of the support chain (including the position of this bushing) every 250 working hours. Check the chain links for any abnormal looseness every 1000 working hours. If there is significant shaking, it may indicate wear of the lining. Replacement timing: When the wear of the inner hole of the liner exceeds the tolerance (obvious steps, excessive clearance), there are serious scratches or deformations, the liner must be replaced together with the matching pin shaft.