2055338 Original Excavator Plate Shim for ZW250

Part number 2055338 is an original plate gasket from Hitachi Construction Machinery, used for connecting the support chain (i.e. chain rail joint) of track type equipment. Therefore, it is mainly suitable for the support chain assembly of Hitachi ZX series medium-sized tracked excavators (such as ZX200, ZX240, ZX330, etc.). Although the ZW250 you inquired about is a wheel loader model and does not involve support chains, this part number (2055338) is a specialized component for excavators. If your device is indeed ZW250, please make sure to check the device nameplate as this part may not be applicable. As a key structural gasket of the original factory, its size, tooth shape, hardness are precisely matched with the supporting chain pin axis and hole position, and it is strictly prohibited to use universal gaskets as substitutes.

This product is a toothed locking gasket, which is formed by stamping a circular steel plate as a whole. The outer edge is processed with a circle of uniform and fine radial serrations. The center is a through-hole used to pass through connecting bolts or pins. Its serrated design has a dual core function: 1 Anti loosening: After installation, the saw teeth bite into the surface of the connecting piece, providing huge mechanical resistance and effectively preventing loosening under severe vibration; 2. Oil storage: The interdental groove can store a small amount of lubricating grease to assist in lubrication and rust prevention. Gaskets are usually made of spring steel, with a surface treated with blackening or phosphating (appearing dark gray in the picture), and have high hardness (HRC 40-50) and excellent rust prevention ability. Its thickness, inner diameter, outer diameter, and sawtooth angle have been accurately calculated to ensure the specified locking torque and anti loosening effect.

Installation specifications: 1 Inspection: Before installation, check whether the gasket serrations are complete, sharp, and whether there is rust or deformation. 2. Cleaning: The installation surface (support chain connection hole plane and bolt/nut contact surface) must be thoroughly cleaned to ensure that there is no paint, rust, or oil stains, in order to ensure that the serrations can effectively bite. 3. Placement: Place the serrated side of the gasket towards the surface of the workpiece that needs to be locked (usually facing under the nut or bolt head). 4. Tightening: Use a torque wrench and tighten it all at once according to the torque specified in the maintenance manual (usually at the level of 200-400 N · m, please refer to the support chain maintenance standard for details). When tightened, the serrations of the gasket will be slightly embedded in the metal surface, achieving self-locking.