Synchronizer rings

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2008 Audi S4, 2008 Audi RS 4, 2007 Audi S4, 2007 Audi RS 4, and 2006 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.

Do not interchange. When reusing synchronizer rings, always install to the same gear.
Check for wear and replace if necessary.

Fig 1: Checking Synchronizer Rings

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Check coated friction surfaces - arrows 2 - from intermediate ring - B - for damage (flat areas, disintegrating areas or carbon layer).
Check inner friction surface - arrow 1 - of synchronizer ring - A - and outer friction surface - arrow 4 - of inner race - C - for grooves and scoring.
On inner race - C - with coated friction surfaces - arrow 3 - , check coating for damage (disintegrating carbon layer).
Coat with gear oil before installing.