Track Adjustment on Dozers

[MikePhua]

Introduction
Proper track tension on a bulldozer is vital for optimal performance, safety, and longevity of the undercarriage components. Track tension affects machine stability, traction, component wear, and overall operational efficiency. Adjusting sag on the tracks corrects loose or overly tight conditions, preventing premature wear or damage.
Signs of Incorrect Track Tension

• Sagging tracks show visible looseness between the sprocket and idler wheels.
  
• Excessive looseness causes instability, track bouncing, and risk of throwing the track off.
  
• Overly tight tracks place damaging stress on pins, bushings, rollers, and the powertrain.
  
• Loud squealing or uneven wear patterns on the tracks indicate misalignment or tension problems.
  

Measuring Track Tension

• Use a rigid straight edge or string laid from the sprocket to the front idler to measure track sag.
  
• Measure the distance from the bottom of this straight edge to the top of the lowest grouser.
  
• Consult the machine-specific operator’s manual for acceptable sag values, typically 2-3 inches for dozers with carrier rollers.
  
• For machines without carrier rollers, measure the sag between sprocket and front idler directly.
  

Track Tightening Process

• Locate the track adjustment valve or grease fitting on the front idler assembly.
  
• To increase tension, add grease slowly using a manual grease gun into the adjustment valve.
  
• Operate the machine forward and backward intermittently to distribute pressure evenly in the adjustment cylinder.
  
• Re-measure track sag and continue adjustment until the recommended sag is reached.
  
• Avoid over-tightening, which can accelerate component wear.
  

Track Loosening Process

• To loosen track tension, locate and carefully open the relief valve on the track adjustment mechanism.
  
• Allow grease to escape slowly, enabling the idler to retract and consequently increasing track sag.
  
• Close the relief valve securely after adjusting.
  
• Re-test track sag after operation for proper slack.
  

Maintenance Tips

• Regular cleaning of the undercarriage removes debris and mud that increase wear.
  
• Inspect track components, including sprockets, rollers, bushings, and carrier rollers for damage or excessive wear.
  
• Replace worn parts promptly to prevent cascading failures.
  
• Monitor track alignment and tension regularly, especially when working in conditions like mud or rocky terrains.
  

Safety Considerations

• Adjust track tension only on level ground with the machine fully stopped and engine off.
  
• Beware of grease under extreme pressure; use protective equipment and follow proper procedures when handling adjustment valves.
  
• Trained personnel should perform track loosening due to safety risks associated with the hydraulic system.
  

Glossary of Terms

• Track Sag: The measured slack or looseness in the track between sprocket and idler.
  
• Carrier Roller: Additional rollers supporting track weight, reducing sag.
  
• Grouser: Raised cleats on the track shoes that dig into terrain for traction.
  
• Track Adjustment Valve: Hydraulic valve regulating pressure in track tension cylinders.
  
• Idler: Front wheel guiding and maintaining track tension.
  

Conclusion
Maintaining correct track tension on a bulldozer is critical for machine safety, durability, and performance. Using accurate measurement methods and following manufacturer guidelines ensures optimal adjustment. Regular maintenance and careful tensioning prolong undercarriage life and reduce costly downtime. Operators and technicians benefit from understanding tensioning procedures and the wear implications of neglected adjustments.