How to Look Up an OEM Part Number

Where to find the OEM number

The most reliable source is the stamp or label on the old part being removed; on most heavy-vehicle parts the number is engraved into the metal body or printed on a durable label, and even if it has faded it can usually be made readable with a magnifying glass or a clean. The vehicle's original parts catalogue or service manual is the next most reliable source, since it shows the number specific to that vehicle by chassis number — this matters especially for parts that changed within the same model across production years. The box or invoice from a previously purchased original part usually has the number printed on it too, and keeping it speeds up future orders. If the number cannot be found anywhere, our technical team can identify the part from the chassis number and the vehicle's make, model and engine details without an OEM number.

What to watch for when reading the number

OEM numbers vary in format by manufacturer: some are purely numeric, while a mix of letters and digits is also common; when reading one, take care not to confuse visually similar characters such as "0" (zero) and "O" (the letter), or "1" and "I". Some manufacturers print a shortened version on the label, with the full number only appearing in the manufacturer's catalogue or system — searching with the short label number alone may return no match. The same number can carry a revision suffix such as "/1" or "A" at the end; this usually marks a minor production change and in most cases does not affect the part's function, but trying the search both with and without the suffix improves the chance of a match. The same number printed in more than one place on the part (for example on both the housing and the box) is usually not a mistake — it can belong to different components of the same assembly.

How cross-reference works

Once you have the OEM number, the next step is to look up its cross-reference equivalents; the same part is often produced by several suppliers under their own stock codes, and these numbers are direct equivalents of one another. A rich cross-reference record improves the odds of finding an equivalent for the same application even when the exact number you have is out of stock. KMQ Otomotiv's OEM reference guide lets you enter the number you have and see which part it corresponds to, which vehicle it fits and its equivalent numbers directly; you can browse the full catalogue from there.

Frequently asked questions

Is the OEM number the same as a stock code?

No. The OEM number is the universal number assigned by the part's manufacturer and does not change. A stock code is an internal reference each supplier assigns to track that part in its own warehouse, and it differs from supplier to supplier.

What if I cannot find the number anywhere?

When the chassis number along with the vehicle's make, model and engine code is sent to our technical team, the correct part can be identified even without an OEM number. A photo of the old part also speeds up the match.