A 3-letter code may be stamped directly onto the housing, usually on the driver's side near the front differential flange.
Common in later A6 models and quattro variants, often identified as ZF8HP . Manual: Examples include 01E or 01X 6-speed units. How to Find Your Gearbox Code audi a6 gearbox codes
A dealer or comprehensive VIN decoder can identify the exact gearbox originally installed. Common A6 Transmission Issues & Fault Codes A 3-letter code may be stamped directly onto
