Allison Transmission Serial Number Lookup -

This is the #1 failure. Allison uses letters O, I, or Q in serial numbers to avoid confusion. If you see a circle, it is a Zero (0). If you see a vertical line, it is a One (1).

Companies like Transend (now part of Veethree) and Mitchell1 Heavy Duty have digitized Allison’s database. Allison Transmission Serial Number Lookup

For many modern units like the 1000 or 2000 series, the data tag is located on the passenger side of the transmission. This is the #1 failure

A: Only if the previous shop uploaded the repair to Allison’s Global Service Database (GSD). Most independent shops do not. Dealers are required to upload warranty work. Allison Transmission Serial Number Lookup