2038877 Original Excavator Driving Disc for Hitachi ZX330

Part number 2038877 is the original drive plate specially designed by Hitachi for the ZX330 series medium-sized hydraulic excavator. It serves as the core transmission connection between the engine flywheel and the hydraulic main pump. Its universal models usually cover 3G series same platform models such as ZX330-3G, ZX350-3G, ZX370-3G, etc. As a key hub for original power transmission, its connection structure, installation hole spacing, and dynamic balance accuracy at both ends are perfectly matched with the engine and main pump

This product is a drive disc made of high-strength alloy steel precision forging, with a cylindrical shape as a whole and a shaft neck with an external spline and locking thread at one end, used to connect and fix with the input shaft of a hydraulic pump; The other end is a flange with seven large weight reduction/installation holes, used for bolted connection with the engine flywheel. Its material and structure have been optimized to withstand the enormous torque of the engine while maintaining good dynamic balance performance, ensuring smooth power transmission. The surface is usually treated with rust prevention, presenting a silver gray color as shown in the picture. Its core function is to efficiently and reliably transmit the rotational power of the engine crankshaft to the hydraulic main pump within a limited space, serving as the "transmission link" for the overall power of the machine.

Installation specifications: 1 Cleaning inspection: Before installation, the engine flywheel joint surface, hydraulic pump shaft, and all joint surfaces of the new drive plate (2038877) must be thoroughly cleaned, and the splines and threads must be checked for damage. 2. Alignment installation: First, smoothly insert the drive plate into the hydraulic pump shaft, ensuring that the splines are fully engaged, and then manually pre tighten the locking nut. Then align the assembly with the engine flywheel, use guide pins to assist, and insert all connecting bolts. 3. Torque tightening: A torque wrench must be used to first tighten the connecting bolts between the drive plate and the flywheel in a cross sequence to the specified torque (usually 150-200 N · m level), and then tighten the locking nut at the pump shaft end (usually higher torque, strictly refer to the manual).