Start with the old part
Most heavy-duty components carry identifying marks: a stamped or cast number, a printed label, or a metal tag. Clean the area gently and photograph it before the part goes in the scrap bin.
If there are several numbers, record all of them. A manufacturer number, a supplier number and a date code can each help narrow down the match.
Record the vehicle
Note the make, model and model year, and the VIN where you can. For engine, transmission and axle parts, the component's own serial or model tag is often more useful than the truck's details alone.
Mid-year production changes are common on commercial vehicles, which is why two trucks of the same model year can need different parts.
Measure what matters
For parts like springs, shocks, hoses and filters, the critical dimensions and connection types decide whether a part fits. Measure carefully and note the units you used.
When in doubt, send photos from several angles with a tape measure in frame. FleetX will confirm the details with you before quoting.
General information only. Always follow the vehicle and component manufacturer's documentation, and have safety-critical work carried out by a qualified technician.