Allison Transmission provides a via their Parts & Service portal.
If you own a heavy-duty truck and a Nexiq USB-Link, you likely have Allison DOC. Allison Transmission Serial Number Lookup
The serial number typically consists of and is usually listed directly below the model number on the data plate. Leading digits often indicate the transmission series: 1000/2000 Series : Starts with 631, 632, or 9308. 3000 Series : Starts with 651, 652, or 9307. 4000 Series : Starts with 661, 662, or 943. AT500/1500 Series : Starts with 321 or 9108. MT600 Series : Starts with 241 or 242. HT/CT 700 Series : Generally starts with 251. 3. How to Perform a Lookup Allison Transmission provides a via their Parts &
Knowing the serial number allows dealers to provide the exact filters, sensors, or internal components required for that specific build. AT500/1500 Series : Starts with 321 or 9108
The serial number is typically found on a metal data plate attached to the transmission housing.
Whether you are a mechanic, a fleet manager, or a buyer like Marco, the process is straightforward:
The serial number is (and also often on the casing). Common locations: