Quick answer
Your semi truck's 17-character VIN (driver-side door jamb, registration, or the plate under the windshield) encodes the exact build — model, GVWR class, engine family and model year. Paste it into PartStop's free VIN lookup (partstop.net/vin) to see only the parts verified to fit that build, or give it to any franchise dealer parts desk to get the exact factory OEM number, then search that number on our catalog for the aftermarket direct replacement.
The 17-character VIN encodes your truck's exact build. Here's what each section means and how VIN-verified fitment kills wrong-part returns.
What the VIN actually encodes
Every truck built since 1981 carries a 17-character VIN. The first three characters identify the manufacturer, positions 4–8 describe the vehicle — model, cab, GVWR class and usually the engine family — position 10 is the model year, and the tail is the serial number. That's enough to pin down the exact platform your parts have to fit.
The VIN never contains the letters I, O or Q (they read like 1 and 0). If you see one, a character was misread — a common source of failed lookups.
Where to find it
- Driver-side door jamb sticker (with GVWR and axle ratings).
- Registration and insurance documents.
- Stamped plate visible through the windshield on the driver side.
Why VIN beats year-make-model for heavy trucks
Two same-year trucks of the same model can carry different engines, mirrors, lighting and brake configurations depending on how they were spec'd. Year-make-model catalogs guess; the VIN doesn't. That's why our VIN search resolves against a verified compatibility database and only shows parts confirmed to fit your build — and why parts managers who buy by VIN see far fewer returns.
From VIN to OEM part number: the dealer route
The VIN also unlocks the exact factory (OEM) part number. Any franchise dealer parts desk — Freightliner/Western Star, Kenworth/Peterbilt (PACCAR), Volvo/Mack, International — can pull your truck's build record from the VIN and read off the precise OEM number the factory installed, including mid-year running changes that year-make-model catalogs miss. The call is free and takes two minutes.
With the OEM number in hand, search it on our catalog: the matching listing is the premium-quality aftermarket direct replacement for that number, typically at a fraction of the dealer counter price. All manufacturer numbers on our site are used for cross-reference and identification only.
No VIN handy? Read the number off the old part
- Most heavy-truck parts carry their number ON the part: molded into plastic housings (mirrors, lights), stamped into metal (brake components, hubs), or on a riveted/stickered ID tag (chambers, valves, sensors).
- Clean the part with a rag before you give up — numbers hide under road film.
- Search that number in our catalog's OEM / cross-reference box; listings match by number, not by look-alike photos.
- Nothing legible? Photograph the part and its mounting, note the truck's VIN, and call (253) 600-1351 — we'll identify it.
Use it on PartStop
Paste your VIN into our free VIN lookup and you'll get the decoded vehicle plus every in-stock part verified to fit it. No lookup match? Call us with the VIN — we'll check fitment manually before you order.
Frequently asked questions
How do I find parts for my semi truck by VIN?
Enter the 17-character VIN at partstop.net/vin — it decodes your truck via the NHTSA database and shows in-stock parts verified against that build. It's free and needs no account.
How do I get the OEM part number from my VIN?
Call any franchise dealer parts desk (Freightliner, PACCAR, Volvo/Mack, International) with the VIN — they pull the build record and read off the exact factory part number free of charge. Then search that number on partstop.net for the direct-replacement aftermarket part.
Why is VIN lookup better than year-make-model?
Two same-year trucks of the same model can be spec'd with different engines, mirrors, lighting and brake configurations. Year-make-model catalogs guess; the VIN identifies the actual build, which is why VIN-verified ordering produces far fewer wrong-part returns.
How fast does PartStop ship?
In-stock orders placed before the daily cutoff ship the same business day (Monday–Saturday) from Tacoma, WA. Standard delivery typically takes ~3 business days, free on orders over $100; overnight is available on most items ($50 small / $150 medium / $300 large parcel).
Shop related parts
Premium-quality aftermarket direct replacements — nationwide same-day shipping, 6+ month warranty.
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.