10-14-2025, 02:55 PM
Track Loss Is Often a Symptom of Undercarriage Wear or Improper Tension
The Takeuchi TB135 is a compact excavator introduced in the early 2000s, known for its reliability and maneuverability in tight spaces. With an operating weight of approximately 7,000 lbs and a dig depth of 10 feet, it’s widely used for landscaping, utility trenching, and light demolition. However, one recurring issue reported by owners is track derailment, especially under moderate load or uneven terrain. When both tracks jump off within an hour, it’s a clear sign that the undercarriage system needs inspection—not just a quick fix.
Sprocket Wear and Chain Mismatch
One of the most common causes of track derailment is worn drive sprockets. As sprockets wear, their teeth become pointed and lose the ability to properly engage the track links. If new rubber tracks are installed without replacing the sprockets, the pitch mismatch between the worn teeth and fresh track lugs can cause the track to ride up and off the sprocket.
To assess sprocket condition:
Idler and Roller Inspection
The idler guides the track at the front of the undercarriage and maintains alignment. If the idler is loose in its frame or the bushings are worn, it can cause the track to drift and eventually derail. Similarly, bottom rollers support the track and distribute weight. Worn rollers can create uneven tension and allow the track to sag or twist.
Inspection tips:
Track Tension and Grease Cylinder Function
Track tension is maintained by a grease-filled hydraulic cylinder that pushes the idler forward. Over time, the tensioner may leak or lose pressure, causing the track to loosen. Over-tightening can also be problematic, stressing the track and components.
To set proper tension:
Terrain and Operator Technique
Track derailment can also result from sidehilling, turning on uneven surfaces, or encountering embedded rocks. Even with proper tension, a track can pop off if it catches a fixed object while turning. Operators should avoid sharp turns on slopes and keep track tension within spec.
Aftermarket Parts and Cost Considerations
Replacing the entire undercarriage can be expensive. Dealer parts for rollers, sprockets, and idlers may exceed $5,000, while aftermarket suppliers like Prowler offer kits for 40–50% less. When choosing parts:
Track derailment on the Takeuchi TB135 is usually caused by a combination of worn sprockets, loose idlers, improper tension, and challenging terrain. A thorough inspection and coordinated replacement of undercarriage components can restore stability and prevent future derailments. These machines are tough—but only when their track systems are treated with care.
The Takeuchi TB135 is a compact excavator introduced in the early 2000s, known for its reliability and maneuverability in tight spaces. With an operating weight of approximately 7,000 lbs and a dig depth of 10 feet, it’s widely used for landscaping, utility trenching, and light demolition. However, one recurring issue reported by owners is track derailment, especially under moderate load or uneven terrain. When both tracks jump off within an hour, it’s a clear sign that the undercarriage system needs inspection—not just a quick fix.
Sprocket Wear and Chain Mismatch
One of the most common causes of track derailment is worn drive sprockets. As sprockets wear, their teeth become pointed and lose the ability to properly engage the track links. If new rubber tracks are installed without replacing the sprockets, the pitch mismatch between the worn teeth and fresh track lugs can cause the track to ride up and off the sprocket.
To assess sprocket condition:
- Inspect tooth profile—pointed teeth indicate wear
- Check for lateral movement or wobble
- Compare pitch spacing to new track specs
Idler and Roller Inspection
The idler guides the track at the front of the undercarriage and maintains alignment. If the idler is loose in its frame or the bushings are worn, it can cause the track to drift and eventually derail. Similarly, bottom rollers support the track and distribute weight. Worn rollers can create uneven tension and allow the track to sag or twist.
Inspection tips:
- Shake the idler manually to check for movement
- Look for chamfering or abnormal wear on roller surfaces
- Measure droop—when lifted off the ground, the track should sag no more than 1 inch
Track Tension and Grease Cylinder Function
Track tension is maintained by a grease-filled hydraulic cylinder that pushes the idler forward. Over time, the tensioner may leak or lose pressure, causing the track to loosen. Over-tightening can also be problematic, stressing the track and components.
To set proper tension:
- Pump grease until the track is taut but still allows 1 inch of droop when suspended
- Clean and inspect the zerk fitting to ensure grease flows freely
- Monitor tension over time—if it drops quickly, the cylinder may need repair
Terrain and Operator Technique
Track derailment can also result from sidehilling, turning on uneven surfaces, or encountering embedded rocks. Even with proper tension, a track can pop off if it catches a fixed object while turning. Operators should avoid sharp turns on slopes and keep track tension within spec.
Aftermarket Parts and Cost Considerations
Replacing the entire undercarriage can be expensive. Dealer parts for rollers, sprockets, and idlers may exceed $5,000, while aftermarket suppliers like Prowler offer kits for 40–50% less. When choosing parts:
- Verify compatibility with OEM specs
- Ask for warranty coverage and wear limits
- Consider replacing all components at once to avoid mismatched wear
Track derailment on the Takeuchi TB135 is usually caused by a combination of worn sprockets, loose idlers, improper tension, and challenging terrain. A thorough inspection and coordinated replacement of undercarriage components can restore stability and prevent future derailments. These machines are tough—but only when their track systems are treated with care.
