Undercarriage Wear Calculator
CalculatorsEnter wear measurements to see percent life left per part and which one governs the rebuild.
Not sure what to check first? Hand the result to the assistant.
About this tool
Undercarriage is the single biggest wear cost on a tracked machine, and remaining life decides whether a used dozer or excavator is a bargain or a money pit. This calculator turns your field measurements into percent life remaining for each component, then flags the governing one - the part that will hit its wear limit first and end the undercarriage's service life.
For each component you measured - link height, bushing outer diameter, grouser height, idler and roller tread, sprocket - enter the new dimension, the discard (worn-out) limit, and your current reading, all in the same unit. Remaining life is a straight interpolation between new and discard: (current − discard) ÷ (new − discard). The new and discard limits come from the OEM or aftermarket wear chart for that model.
Vendors keep this behind "send us your measurements" forms to capture a sales lead. The math is public - this does it instantly. It is a reference estimate: bring a worn undercarriage to a dealer or use ultrasonic measurement for a purchase decision.
Frequently asked questions
Where do I find undercarriage wear limits (new and discard dimensions)?
From the model's undercarriage wear chart - OEM (Cat, Komatsu) or aftermarket (ITR, Berco, CTP) publish them. The discard dimension is the 100%-worn service limit. If you only have current readings, ask on the forum for the chart for your model.
Why does the most-worn component govern?
The undercarriage is 'worn out' when any single component reaches its discard limit, because running past it damages mating parts. So remaining life is set by the lowest component, not the average - plan the rebuild around it.
Do I measure undercarriage wear in millimetres or inches?
Any - millimetres or inches - as long as new, discard, and current are all in the same unit. Remaining life is a ratio, so the units cancel out.
Can I measure without pulling the machine apart?
Link height, grouser height, and bushing OD can be measured with a wear gauge or calipers on the machine. Precise pin/bushing internal wear needs ultrasonic gear, which is why dealers push their inspection service.
Is this accurate enough to buy a machine on?
Use it to screen and negotiate. For a final purchase decision on an expensive machine, get a professional ultrasonic undercarriage inspection - it reads internal wear this surface-measurement method can't.