final drive flange

This is the part for which Honda specifies the high moly grease, because it's a severe service application. Many of our old bikes went many miles without this special lube there, and then worn out teeth result. They should be cleaned and relubed each time the rear tire is replaced. It's best to replace them as a set. Good used ones should not be too difficult to find, except you have jinxed yourself by telling the gremlins you need a set fast.