History.. I installed these gears(4.56 Richmond), about 10 years ago. Pattern good, BL was at .010". Over the years of street and race driving, there was no noise. Gradually, starting about 2 years ago I started noticing a gear whine/whorrling noise when coasting or maintaining speeds on the street. With open headers, you really can't hear any noise at all...On the street, the noise is like an on/off whine when maintaining a speed, any speed... When on power there is no noise at all. Quite as a mouse. I think I know what is going on, but wanted confirmation. SO, what do you professionals think is going on?? By the way, all bearings were replaced when installed and the rear has never been run low on fluid..