You are conducting a pre-operational inspection on an excavator and notice that the track sag on the left side is noticeably tighter than on the right side, despite the tensioner being set evenly. What is the most probable cause for this discrepancy?

Question: You are conducting a pre-operational inspection on an excavator and notice that the track sag on the left side is noticeably tighter than on the right side, despite the tensioner being set evenly. What is the most probable cause for this discrepancy?

Answer options: ✅ A worn or seized track roller on the left side, causing increased tension.

• A stretched track chain on the right side over time, leading to more sag.
• A malfunctioning track tensioner on the right side, not properly applying tension.
• Uneven ground conditions during the inspection, distorting the perception of sag.

Correct answer: A worn or seized track roller on the left side, causing increased tension.

Explanation: While track tensioners and stretched chains can cause sag discrepancies, a worn or seized track roller on one side would directly increase the effective tension on that section of the track, even if the tensioner is set correctly, leading to a tighter sag. Uneven ground can affect the visual inspection, but wouldn't cause a fundamental difference in sag if the machine is parked on a relatively flat area as is standard for checks.