Understanding and Resolving Track Tension Issues in Kubota Mini Excavators

[MikePhua]

Kubota mini excavators, renowned for their compact design and versatility, are equipped with rubber tracks that provide traction and stability. Maintaining proper track tension is crucial for optimal performance and longevity of the machine. Over time, various factors can lead to issues with track tension, including slack tracks, inability to adjust tension, or tracks coming off. This article delves into the common causes of track tension problems in Kubota mini excavators and offers practical solutions.
Common Causes of Track Tension Issues

1. Over-tightened Tracks: Excessive tension can lead to increased wear on rollers and sprockets, reduced power, and potential track damage.
   
2. Under-tightened Tracks: Loose tracks may cause derailing, especially on slopes, and can lead to uneven wear.
   
3. Inability to Adjust Tension: If the track adjuster valve is clogged or malfunctioning, it may prevent proper tension adjustment.
   
4. Tracks Coming Off: Improper tension or worn components can cause tracks to derail.
   

Adjusting Track Tension
Proper track tension is essential for the efficient operation of Kubota mini excavators. The track tension is controlled by a track adjuster located behind the front idler. Adjustments are made by pumping or draining grease through the track adjuster valve. Even small adjustments in track sag have a significant impact on tension. A change in sag from 1 inch to 0.5 inches increases tension by about 3,000 pounds.
Steps to Adjust Track Tension:

1. Position the Excavator: Park the excavator on flat, level ground. Lift the dozer blade to its highest position. Ensure the boom and arm are perpendicular to the tracks, then lower the boom so the tracks lift off the ground by about 10 centimeters (4 inches).
   
2. Remove the Track Tension Cover Plate: Locate the track tension adjustment cover plate. Using a wrench, remove the bolts securing the cover plate to access the adjustment components.
   
3. Adjust the Track Tension: With the cover removed, you'll see a tension adjustment rod with a locknut. Loosen the locknut to allow adjustment of the tension rod. To tighten the track, turn the adjustment rod clockwise to push the idler forward. To loosen the track, turn the rod counterclockwise.
   
4. Secure the Adjustment: Once the correct tension is achieved, tighten the locknut to secure the adjustment rod in place.
   
5. Reinstall the Cover Plate: After adjusting the track tension, replace the cover plate and secure it with bolts to protect the tensioning mechanism.
   

Troubleshooting Track Tension Issues
If you encounter difficulties with track tension adjustment, consider the following:

• Clogged Grease Valve: The grease valve may be clogged, preventing grease from entering or exiting the adjuster. Remove the valve and clean it thoroughly.
  
• Seized Track Adjuster: Over time, the track adjuster can become seized due to rust or debris. In such cases, applying penetrating oil and gently tapping the adjuster with a hammer may help loosen it.
  
• Worn Components: Inspect the track adjuster, idler, and rollers for signs of wear. Worn components may need to be replaced to restore proper track tension.
  

Preventative Maintenance Tips
To prevent track tension issues:

• Regular Inspections: Periodically check track tension and adjust as needed.
  
• Clean Components: Keep the track adjuster and surrounding areas clean to prevent debris buildup.
  
• Proper Lubrication: Ensure the track adjuster is properly lubricated to prevent rust and wear.
  
• Avoid Overloading: Do not exceed the machine's rated capacity, as excessive weight can strain the tracks and adjuster.
  

Conclusion
Maintaining proper track tension in Kubota mini excavators is vital for optimal performance and longevity. Regular adjustments and inspections, along with addressing any issues promptly, can prevent costly repairs and downtime. By understanding the causes of track tension problems and implementing effective solutions, operators can ensure their machines operate efficiently and safely.