1033158 Original Excavator Gearbox Housing for ZX200-3

Part number 1033158 is the original pump device gearbox housing (also known as gear housing/transfer case housing) provided by Hitachi Construction Machinery for the ZX200-3 series 20 ton medium-sized hydraulic excavator. This component is mainly used as a power transmission mechanism between hydraulic pumps and engines, serving as a sealing and supporting housing for gear transmission systems. Its universal models cover 20 ton models such as Hitachi ZX200-3, ZX200-5, EX200-3, as well as some older excavators on equivalent platforms such as ZX200-2 and EX200-2. As a high-precision cast shell from the original factory, its installation holes and sealing surfaces are precisely matched with the pump body and engine flywheel housing. The use of non-standard spare parts is strictly prohibited to avoid poor gear alignment, oil leakage, or shell cracking.

This product is an original cast iron or cast aluminum shell, usually made of HT250 gray cast iron or ZL1101 cast aluminum, which has undergone aging treatment and precision machining. Typical technical parameters: wall thickness of 8-15mm, installation flatness ≤ 0.05mm, bearing hole accuracy of H7 level, sealing surface roughness Ra1.6. The interior of the shell is equipped with lubricating oil passages, oil return chambers, and ventilation holes, while the exterior integrates lifting holes, positioning pin holes, and sensor interfaces. Its structure complies with JIS G 5501, GB/T 9438 and other standards, with a working temperature of -30 ℃ to+120 ℃ and a maximum bearing torque of ≥ 800N · m.

Disassembly inspection: Before replacement, the hydraulic pipeline must be disconnected and the gearbox lubricating oil must be drained completely. After removing the shell, check the sealing surface for scratches and corrosion, measure the diameter of the bearing hole (allowable wear ≤ 0.03mm) and the flatness of the installation plane (tolerance ≤ 0.10mm). Installation points: 1 Clean the joint surface of the shell and evenly apply flat sealant (recommended Loctite 574); 2. Tighten the installation bolts step by step in a cross sequence (usually with a torque of 60-80N · m); 3. After installation, add the specified gear oil (model GL-5 80W-90, capacity 3-5L). Operation test: After assembly, start the engine and run it at idle speed for 15 minutes to check for any leakage or abnormal noise in the housing, and monitor whether the oil temperature is normal.