Undercarriage parts for submerged service
These are the components that wear fastest on an amphibious machine: rollers, bushes, pins, links, sprockets and the seals that protect them. All of it runs submerged in abrasive silt for most of its working life, which is why consumption here dominates the parts budget.
Measure, do not estimate
Visual inspection consistently underestimates undercarriage wear — components look serviceable well past the point where they are accelerating wear on everything they contact. Measure against the wear limits on a schedule and replace on the measurement rather than on appearance.
Salt and brackish water
Treat this as a separate category. Corrosion compounds abrasive wear rather than simply adding to it, and replacement intervals shorten substantially. If the machine has worked in salt or brackish water, say so when ordering — it changes what is worth fitting.
