4639326 Hitachi Original Excavator Cushion for ZX670-3 ZX870-3

Hitachi original excavator cushion (universal part number: 4639326) is a key support and shock absorber component in the engine installation system, commonly referred to as the engine front seat cushion or foundation pad. This original spare part is mainly suitable for multiple large excavators from Hitachi, commonly found in models such as ZX650LC, ZX670-3, ZX870-3, etc. It is installed between the excavator chassis and the front bracket of the engine to support the weight of the engine and isolate vibrations.

The core function of this cushion is to serve as a structural cushioning and support element between the engine and the chassis. Its main functions include: bearing the static weight and dynamic load of the engine; Effectively absorb and isolate the vibration and impact generated during engine operation, prevent direct transmission of vibration to the main structure of the excavator, thereby protecting other precision components, reducing noise, and improving operational comfort; At the same time, it can also compensate for minor unevenness on the installation surface, ensuring stable engine installation.

The core of engine seat cushion maintenance lies in regularly checking its physical condition and timely replacement. It is recommended to check the cushion block for obvious compression deformation, cracking, delamination, metal corrosion, or rubber hardening failure every 1000 hours of work or every 6 months. During inspection, attention should be paid to whether there are any abnormal vibrations transmitted to the body of the engine under idle and load conditions. When cleaning the installation contact surface, avoid using highly corrosive solvents. Once the cushion block loses elasticity, cracks appear, or causes engine installation looseness or increased vibration, it must be replaced immediately.