This is the primary portal for professional lookups. The Allison HUB Parts Catalog allows you to search by Serial Number to find assembly and detail part numbers.
Allison Transmission Serial Number Lookup: The Ultimate Identification Guide Allison Transmission Serial Number Lookup
A small silver or colored plate. You will need to wipe away dirt or grease to read the digits. This is the primary portal for professional lookups
On older or specific vocational models, the tag may be on the lower rear face of the rear housing or near the bellhousing. Allison Transmission Serial Number Lookup
The most reliable way to identify your transmission is to locate the (nameplate) attached directly to the transmission housing.