To perform an Allison Transmission serial number (S/N) lookup, you must first locate the physical data tag on the unit. This 10-digit number is the "key" to identifying the exact build configuration, parts, and warranty history through official Allison tools. 1. Where to Find the Serial Number
- Left side (driver’s side) of the transmission housing, near the data plate.
- On a flat pad near the oil fill tube or main control valve body.
- For older models (e.g., AT, MT, HT series): near the top, just behind the bell housing.
- For 1000/2000/3000/4000 Series (2000s–present): on a barcode label and stamped near the rear of the case.
The serial number is found on the identification plate (data tag) located on the exterior of the transmission housing.
Where is the Serial Number Located?
Allison transmission serial numbers are stamped on a metal data plate (tag) attached to the transmission housing. The location varies depending on the series.
The Plate That Tells a Life Story
- When you enter a Serial Number into a dealer portal or a site like Detroit Diesel Allison (DDC) or AllisonHub, the system cross-references it to a specific PLN.
- The PLN is the "DNA" of that specific unit. Two transmissions with identical Serial Numbers are impossible; two transmissions with identical Model Numbers might have zero interchangeable parts.
Vehicle Identification Plate: Often found on the left side of the operator's cab or cowl.
- What the Allison serial number is and why it matters
- Third‑party lookup methods and limitations