Caterpillar
CAT parts are listed by model, with the price on every listing. The 300-series minis, 301.6 and 301.6C, 302.5 and 302.5C, 303.5 and 303.5E, 304, 305 CR, 307C, 308 and 308D, are listed in the Machinery Parts Finder with their parts matched to the model, and the 320 track adjuster sits with them. The D-series dozers, the 400-series backhoes and the 900-series loaders follow.
CAT rubber tracks and track adjusters: 301.6, 302.5, 303.5, 308, 320
Undercarriage is the deepest CAT range: rubber and steel tracks, track shoes, rollers, idlers, sprockets and adjusters, listed against the CAT model with width, pitch and link count on the listing. Track presses and pin presses sit with them, because CAT track service is a press job.
CAT starters, injectors and bucket teeth: D-series, 400-series, 900-series
Starter motors and alternators and fuel pumps and injectors are listed against the model, the electrical parts with OE number and voltage. Bucket teeth, adaptors and cutting edges run deeper for CAT than for any other make here. Radiators follow.
The serial prefix on the plate settles which generation you have, and the Machinery Parts Finder takes it: choose the make, the model from the dropdown, then the part type. Some models have their own pages; start there if yours does. A CAT part number goes straight into the header search. When the plate is gone, a photo to 07754288583 on WhatsApp does the job. The Compatible tab confirms the fit.
Turbochargers by engine sit in the wider range with oil to the CAT grade through the Oil Finder, batteries, filters and the rest, matched by specification rather than by machine. PartsForMachines lists all of it. Not in the Finder? Ask Simon.