Hitachi Construction Machinery’s bulldozers enjoy a high reputation in the global construction machinery market for their excellent performance and durability, and are widely used in heavy-duty construction fields such as earthwork and mining operations. However, in a high-intensity construction environment, even high-quality equipment may cause reducer failures due to long-term use or improper maintenance. As a core component of power transmission, the reducer will directly affect the operating efficiency and equipment life of the bulldozer once an abnormality occurs. This article will analyze in detail the common fault types of Hitachi Construction Machinery bulldozer reducers and their scientific treatment methods to help equipment managers prevent and solve problems more effectively.
Reducer overheating phenomenon
In the heavy-duty operation of Hitachi ZD220-3 and D375A-6 bulldozers, reducer overheating is a common fault manifestation. When the bulldozer is in long-term high-load operation, if the reducer is poorly lubricated or the cooling system is abnormal, it will often cause the high-speed operation of the gears to generate a lot of heat, causing the reducer temperature to rise abnormally. Excessive temperature will not only accelerate the oxidation and deterioration of lubricating oil, but also may cause premature wear of internal bearings and gears.
To solve the problem of overheating, it is necessary to check the type and amount of lubricating oil, ensure that the high-temperature wear-resistant lubricating oil recommended in the equipment manual is used, and maintain the oil level within the standard range. If the lubricating oil is normal but the temperature is still high, it is necessary to check whether the ventilation and heat dissipation system outside the reducer is blocked. If necessary, forced air cooling equipment can be added. In addition, the lubricating oil should be replaced regularly to prevent the lubrication performance from deteriorating due to oil aging.
Abnormal noise and vibration
During the operation of ZD220-3 and D275AX-5 bulldozers, the transmission part of the reducer may have abnormal noise or obvious vibration. Abnormal noise and vibration of the reducer usually come from abnormal meshing of internal gears or bearing damage. When the gears inside the reducer are severely worn, the meshing clearance increases, or the rolling elements of the bearings are peeled off and damaged, the bulldozer may emit sharp metal friction sounds or periodic vibrations during operation. The main causes of such failures may be long-term overload operation of the equipment, insufficient lubrication, or insufficient gear accuracy.
To solve the problem of abnormal noise and vibration, it is necessary to stop the machine and check the wear of the gears and bearings inside the reducer. If the gears are found to have obvious pitting, peeling or tooth surface wear, the damaged parts should be replaced in time. At the same time, when replacing new parts, original genuine accessories should be selected to ensure that the gear accuracy and hardness meet the original factory standards. In addition, the bearing installation clearance should be checked to ensure that it meets the standard specifications to prevent secondary damage caused by improper assembly.
Reducer oil leakage problem
Oil leakage is one of the more common faults of Hitachi Construction Machinery bulldozer reducers. It usually occurs when the oil seal is aging, the box seal is poor, or the fastening bolts are loose. Oil leakage not only leads to insufficient lubrication, but also may pollute the construction site and bring additional cleaning costs. Especially in extreme working conditions (such as muddy or dusty environments), oil leakage may also accelerate external impurities to enter the reducer, further damaging the gears and bearings.
When oil leakage occurs, first check whether the oil seal is aging, cracked or deformed. If the oil seal is found to be damaged, it should be replaced with a new original oil seal immediately and reapplied with sealant to ensure that there is no foreign matter left on the sealing surface. In addition, it is also necessary to check the plane joint of the reducer housing. If there are casting defects or deformations, it is necessary to grind and repair or replace the reducer housing. At the same time, be sure to check the tightness of the housing bolts to prevent loosening due to vibration.
Transmission failure and insufficient power
The transmission failure or insufficient power output of the reducer is mostly related to gear damage, output shaft breakage or internal transmission chain breakage. When the bulldozer reducer gear is broken or severely worn, the power cannot be transmitted normally, which is manifested as the equipment being powerless or losing power when operating under load. In addition, internal wear caused by insufficient lubrication may also cause similar symptoms.
In the face of this fault, it is necessary to stop the reducer and disassemble it for internal inspection. If the gear is found to be damaged, the damaged gear set must be replaced immediately, and the meshing surfaces of other gears must be checked for abnormal wear. For the problem of insufficient power caused by insufficient lubrication, replacing the lubricating oil and cleaning the oil circuit are necessary measures. In addition, the hydraulic system and engine transmission part of the bulldozer should also be checked to eliminate other power transmission faults other than the reducer.
As the core component of high-load and high-intensity working equipment, daily maintenance and timely troubleshooting of Hitachi Construction Machinery’s bulldozer reducers are essential for the stable operation of the equipment. To reduce the failure rate of reducers, the following measures are recommended:
Regularly check and replace the lubricating oil status to ensure that the oil quality meets the standards and avoid wear caused by insufficient lubrication.
Follow the load use specifications and avoid long-term overload operation. The reducer should operate within the rated operating range.
Pay attention to abnormal noise and vibration. When abnormalities occur, the machine should be stopped and checked immediately to avoid minor faults from turning into major damage. At the same time, check the gear meshing and bearing wear status regularly.
Use original accessories. When replacing parts, make sure to use Hitachi Construction Machinery’s original accessories to ensure performance matching.
If you need to purchase high-performance reducers or get more professional maintenance advice, please visit our Reducer Online Store or contact us directly via WhatsApp: +86 18015057952. We will provide you with professional reducer selection and maintenance solutions to help your equipment maintain excellent performance.