Allison Transmission Serial Number Lookup [repack] -

For newer trucks or well-documented fleets, the transmission model may appear on the build sheet, window sticker, fleet maintenance records, or owner's manual. This method is convenient but less reliable than the physical tag.

Confirms whether your unit requires TES 295, TES 668, or other specialized fluids.

Internal components like filters, valve bodies, and electronic control modules (ECMs) change based on assembly numbers.

A fleet manager searches serial 6510823456 and discovers the transmission was originally built for a 2019 International HV607 with a 3000 HS (high-speed) output. Without this lookup, they would have ordered a standard 3000 output shaft seal—which would leak immediately. Allison Transmission Serial Number Lookup

Mechanics need the serial number to download correct shifting profiles and software patches to the Transmission Control Module (TCM).

(metal nameplate) physically attached to the transmission housing. : Look on the passenger side

The serial number provides access to the transmission's build date, factory configuration, and service history. This information is crucial for planning preventative maintenance, tracking the remaining life of wear components, and ensuring that your transmission receives appropriate care based on its specific specifications. For newer trucks or well-documented fleets, the transmission

To help find your transmission information quickly, could you share the of your vehicle? If you have already located a number on the casing, tell me how many digits it has so I can help verify if it is the correct serial string.

On many Allison identification tags, a date of manufacture number is also present. This number typically follows a format such as "05J12," which decodes to November 12, 2005. The letter corresponds to the month (A = January, B = February, C = March, D = April, E = May, F = June, G = July, H = August, I = September, J = October, K = November, L = December), and the numbers represent the day and year.

Typically located on the passenger side (right side) near the rear corner of the transmission oil pan. Mechanics need the serial number to download correct

While the exact position can vary slightly by model, the ID tag is generally located on the main housing of the transmission. You will likely need to safely crawl under the vehicle to find it. Here are the most common locations:

This means that if your serial number begins with "63," you have either a 1000 or 2000 Series transmission. If it begins with "65," it is a 3000 Series unit. If it starts with "66," you have a 4000 Series transmission.