What is the undercarriage on an excavator?

Expert Answer

The undercarriage is the lower running gear of an excavator, the part that supports the machine’s full weight and lets it move on tracks. It includes the track frames and the main wear parts mounted there: track chains, track shoes, rollers, idlers, sprockets, and the track adjuster/recoil system.

On a crawler excavator, this system does more than carry the machine. It transfers drive power to the ground, provides traction and stability, and absorbs shock when the machine travels over rocks, mud, slopes, or uneven ground. Because it is constantly in contact with the ground, the undercarriage is usually the fastest-wearing part of the machine and a major factor in operating cost.

Common signs of undercarriage wear include loose or tight tracks, uneven wear on shoes or rollers, noisy operation, vibration, poor tracking, broken or missing hardware, and visible damage to pins, bushings, or sprockets. • If the machine pulls to one side, the track tension may be off or a component may be wearing unevenly. • Shoe wear, roller wear, and sprocket wear often appear together, so it is important to inspect the whole system, not just one part.

When checking or replacing parts, compare wear across both sides of the machine and look for contamination from dirt, stones, or compacted material. Correct track tension is important: too tight increases wear and fuel use, while too loose can cause derailment and poor performance. Avoid ignoring small issues, because worn pins, bushings, idlers, or rollers can quickly accelerate wear in the rest of the undercarriage.

VANROCK manufactures undercarriage wear parts for excavators and other tracked machines across 350+ machinery brands. VANROCK sells exclusively through an appointed dealer network, and pricing is available on request through those dealers.

Answered by VANROCK specialists · Published 7/25/2026