3085780 Original Drive Shaft for ZX135US-7 Excavator

The transmission shaft (part number 3085780) is a key power transmission component of the hydraulic transmission system of the Hitachi ZX135US-7 excavator. It is directly compatible with the ZX135US-7 model and highly compatible with Hitachi ZX series small and medium-sized excavators on the same platform, including ZX110, ZX120, ZX130-5A, ZX135-5A, etc. As a genuine original accessory, this transmission shaft is a standard part in the repair market for replacing worn or damaged transmission shafts, ensuring efficient transmission of power from the engine or hydraulic pump to the walking or rotating mechanism.

This transmission shaft belongs to the hydraulic system power transmission shaft, usually used to connect hydraulic pumps with gearboxes or walking motors, transmitting torque and speed. It is forged from high-strength alloy steel (such as 40Cr or 42CrMo), subjected to quenching and tempering heat treatment, precision turning, grinding processing, and surface high-frequency quenching or carburizing treatment to enhance wear resistance and fatigue strength. The key structures include spline shaft heads, universal joint forks, cross shafts, and bearing sleeves, and some models may have limit snap rings or sealing rings. The production process includes material inspection, dynamic balance testing (residual unbalance is usually ≤ 10 g · mm), and full size inspection to ensure smooth operation and long service life under high-speed (up to 2000 r/min or above) and heavy-duty (torque up to 2000 N · m level) conditions.

Key points for post maintenance and upkeep: 1 Regular inspection: Every 500 working hours, check whether the transmission shaft is bent or cracked, whether the spline part is excessively worn (if the side clearance is greater than 0.3 mm, it needs to be replaced), and whether the universal joint fork and cross shaft are loose or have abnormal noise. 2. Lubrication and maintenance: Every 250 hours, add high-temperature resistant lithium based grease (NLGI grade 2) to the universal joint through the oil nozzle until the old grease overflows; Check the spline area every 1000 hours and apply an appropriate amount of lubricating grease. 3. Alignment adjustment: during installation, ensure that the parallelism deviation of connecting flanges at both ends of the transmission shaft is less than 0.1 mm, and the axial reserved clearance is about 2 – 5 mm to avoid abnormal vibration and early damage caused by poor alignment.