WARNING: This page is about a different car, the 2008 Audi A4, 2007 Audi A4, 2006 Audi A4, and 2005 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Pressing On 1st And 2nd Gear Synchronizing Hub
Courtesy of VOLKSWAGEN UNITED STATES, INC.
Installation position:
High inside collar faces 2nd gear.
The lugs of 1st gear synchro-ring and recesses on synchronizing hub must align - arrow
- when pressing on.