Undercarriage and wear parts for amphibious machines and extended fronts. These are the items that move fastest, because a submerged undercarriage wears at a rate that has little relationship to the hour meter.
A dry-land undercarriage sheds soil as the chain articulates. A submerged one holds fine silt in the pin and bush interfaces, where it works as a continuous grinding paste under full machine load. Operators arriving from conventional machines routinely underestimate the consumption.
When ordering, send the machine class and a photograph showing any casting or stamping marks on the existing part. That identifies components more reliably than a part number, since numbering differs between suppliers and changes over time.