WARNING: This page is about a different car, the 2024 Audi S6 and 2024 Audi A6 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
-- Check the torque converter hub -arrow- for wear grooves.
Fig 1: Checking Torque Converter
Courtesy of AUDI OF AMERICA, LLC
The torque converter must be replaced if it is damaged or faulty.