Hitachi EX60-2 Final Drive: Maintenance and Troubleshooting Guide

[MikePhua]

The Hitachi EX60-2 is a compact, powerful excavator known for its reliable performance in various construction and excavation tasks. Like any piece of heavy equipment, maintaining the final drive is crucial to ensure long-lasting operation and avoid costly repairs. The final drive is a critical component of the undercarriage, responsible for transmitting the power generated by the engine to the tracks, allowing the machine to move efficiently. If the final drive malfunctions, it can lead to decreased machine performance, increased fuel consumption, and, in the worst cases, a complete breakdown of the tracks.
In this guide, we will delve into the maintenance and troubleshooting of the final drive on the Hitachi EX60-2 excavator, exploring common issues, diagnostic tips, and recommended solutions.
Understanding the Final Drive System
The final drive system in the Hitachi EX60-2 is responsible for converting the power from the engine and transmitting it to the drive sprocket, which then propels the tracks. The system consists of several components, including:

1. Hydraulic Motor: This motor provides the driving force by converting hydraulic fluid pressure into rotational motion, powering the final drive.
   
2. Planetary Gearbox: The hydraulic motor drives a planetary gearbox, which reduces the speed and increases the torque before transmitting it to the tracks.
   
3. Track Drive Sprocket: This component is connected to the final drive gearbox and is responsible for driving the tracks.
   
4. Bearings and Seals: Bearings allow smooth rotation, while seals prevent dirt and moisture from contaminating the system.
   

When these components are well-maintained, the final drive operates smoothly, ensuring reliable movement and performance of the excavator.
Common Issues with the Final Drive
Several problems can arise in the final drive of the Hitachi EX60-2. Understanding these common issues can help in early detection and prevent more severe damage.

1. Leaking Seals
   Over time, the seals in the final drive can wear out, causing hydraulic fluid to leak. This not only reduces the efficiency of the system but can also lead to overheating and further damage if not addressed promptly. Regularly inspecting the seals and replacing them as needed is essential for maintaining the final drive's functionality.
   • Solution: Check the final drive for any signs of fluid leakage. If you notice a leak, inspect the seals for wear and replace them as necessary. Ensure the hydraulic fluid levels are maintained within the recommended range.
     
2. Worn-out Bearings
   Bearings in the final drive allow the components to rotate smoothly. Over time, the constant pressure and heat generated during operation can cause the bearings to wear out, leading to poor performance, excessive noise, or even failure of the final drive.
   • Solution: If the final drive is producing abnormal noise or shows signs of excessive wear, such as increased friction or heat, it's crucial to inspect the bearings. Replacing the bearings before they fail can prevent a more expensive repair.
     
3. Damaged Gearbox
   The planetary gearbox reduces the speed of the hydraulic motor while increasing torque, transferring it to the tracks. If the gearbox becomes damaged, typically due to a lack of proper lubrication or excessive strain, it can lead to significant problems with the final drive.
   • Solution: Regularly check the gearbox for any signs of damage, including cracks or excessive wear. Ensure that the gearbox is properly lubricated and that the oil levels are maintained. If any damage is found, the gearbox may need to be replaced.
     
4. Hydraulic Motor Failure
   The hydraulic motor is the driving force behind the final drive, and if it fails, the entire system will stop functioning. This could be caused by issues like contamination, improper maintenance, or poor hydraulic fluid quality.
   • Solution: To avoid hydraulic motor failure, perform routine maintenance, including checking hydraulic fluid levels and ensuring that the fluid is clean and free of contaminants. If the hydraulic motor is malfunctioning, it may need to be replaced or rebuilt.
     
5. Track Slipping or Uneven Movement
   If the final drive is not functioning properly, the tracks may slip, resulting in uneven movement or reduced traction. This issue can be caused by a number of factors, including worn-out components, insufficient lubrication, or leaks in the system.
   • Solution: Ensure that the final drive is properly lubricated and that there are no fluid leaks. If the problem persists, check the drive sprocket and the bearings for signs of wear. Uneven track movement may also indicate a misalignment or mechanical failure in the final drive components.
     

Diagnosing Final Drive Problems
When troubleshooting the final drive on the Hitachi EX60-2, it’s important to follow a systematic approach. Here are the steps you should take to diagnose the issue:

1. Visual Inspection
   Start by performing a thorough visual inspection of the final drive. Look for any visible signs of wear, leakage, or damage. Pay attention to the hydraulic fluid levels, the condition of the seals, and the appearance of the bearings and gears.
   
2. Check for Unusual Noise
   Listen for any abnormal noises, such as grinding, whining, or clicking. These sounds can indicate worn-out bearings or damaged gears inside the final drive.
   
3. Monitor Performance
   Test the machine’s performance while operating. Pay attention to any signs of slippage, uneven movement, or difficulty in turning. These symptoms may point to an issue with the final drive components.
   
4. Check Fluid Levels
   Ensure that the hydraulic fluid levels are correct and that the fluid is clean. Low or dirty fluid can lead to insufficient lubrication, which can cause the final drive components to overheat and wear out.
   
5. Test the Sprocket
   Check the drive sprocket for excessive wear or misalignment. If the sprocket is damaged or worn, it can affect the efficiency of the final drive.
   

Preventative Maintenance for the Final Drive
Proper maintenance is key to extending the lifespan of the final drive in the Hitachi EX60-2. Here are some important maintenance tips to follow:

1. Regular Lubrication
   Ensure that the final drive components are well-lubricated. Proper lubrication reduces friction, prevents overheating, and minimizes wear on the bearings and gears.
   
2. Monitor Hydraulic Fluid Levels
   Regularly check the hydraulic fluid levels and replace the fluid as recommended by the manufacturer. Use the right type of hydraulic fluid to prevent contamination and ensure optimal performance.
   
3. Inspect Seals and Bearings
   Periodically check the seals for wear and replace them if necessary. Inspect the bearings for signs of wear or damage and replace them before they cause further issues.
   
4. Perform System Flushes
   Flushing the hydraulic system periodically helps remove contaminants that can cause damage to the final drive and other hydraulic components.
   
5. Track Alignment
   Ensure that the tracks are properly aligned and that there is no misalignment in the final drive system. Misalignment can cause excessive wear on the sprockets and other components.
   

Conclusion
The final drive on the Hitachi EX60-2 is a critical component that plays a major role in the overall performance of the excavator. Regular maintenance and early detection of problems can prevent costly repairs and extend the lifespan of the equipment. By understanding common issues, performing routine checks, and keeping up with preventative maintenance, operators can ensure that the final drive functions smoothly and efficiently for years to come. Whether you're operating in construction, landscaping, or demolition, taking care of your machine's final drive is essential for optimal performance.