Allison Transmission Serial Number Lookup [TESTED]

Typically found on the passenger side (right side) of the transmission.

: The SN reveals the "Assembly Part Number," which dictates how the transmission was programmed and geared for its specific vehicle. 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 Typically found on the passenger side (right side)

Provides historical build and shipment data, as well as warranty claim history. Allison Authorized Service Network: AT500/1500 Series : Starts with 321 or 9108