How to Check and Adjust Excavator Track Tension
Correct track tension is one of the cheapest ways to extend undercarriage life. Here is how to measure sag, adjust the tension safely and avoid the most common mistakes.
Tracks that are too tight wear pins, bushings, sprockets and idlers rapidly and waste fuel. Tracks that are too loose can derail and slap. Checking tension takes a few minutes and pays back many times over.
How track tension works
A track adjuster behind the front idler contains a grease cylinder and a large recoil spring. Pumping grease into the cylinder pushes the idler forward and tightens the track; releasing grease loosens it.
Measuring sag (typical method)
- Park on firm, level ground, ideally in the material you work in.
- Travel forward a few metres and stop, so slack collects at the top.
- For excavators, many manuals specify raising the track with the boom and measuring sag between the track frame and the bottom of the shoe at the middle roller; others measure top sag between the carrier roller and idler.
- Compare with the specification in your manual (for many mid-size excavators the target is roughly 30–40 mm or about 1.2–1.6 in, but check your model).
Adjusting
- To tighten: pump grease into the adjuster fitting.
- To loosen: slowly open the relief valve (usually one turn at most) and let grease escape. Never stand in front of the valve and never remove the fitting: the grease is under very high pressure.
- Re-measure after travelling a few metres.
Adjust for conditions
Run slightly looser in mud and sticky soils that pack into the undercarriage; tighter in hard, rocky ground only within the manual's range.
Warning signs
- Grease leaking from the adjuster (seal failure).
- Track that keeps loosening.
- Sprocket teeth wearing to points.
See our full undercarriage wear guide.
