A:You might be talking about the throw out bearing behind the transmission side cover.
View @ 6:20 http://www.fixmyhog.com/video/jims-transmission-side-cover-install-006927/
Clutch adjustment should be as follows:
Incorrect clutch adjustment is the most common reason for throw-out bearing failure. The bearing is only supposed to be engaged when the clutch lever is pulled inward. That is one of the reasons why it is so important to completely slacken the clutch cable BEFORE adjusting the clutch pack and, also, why you need to correctly back out the adjuster screw. If the bearing is constantly engaged, it will be subject to excessive heat and, therefore, fail.
Other reasons for throw-out bearing failure are: age/high miles/a lot of city riding/lack of maintenance (bad, old, or wrong oil)/Incorrect oil level/aftermarket side cover (binding of ball & ramp assembly)/heavy spring load from aftermarket performance clutch assembly.