I have a 2001 sportster. 80% of the time it make a howling noise from the front case area possible where the belt drive is. When its making the noise I can put it in neutral or any gear with the clutch in or out,coast even with the engine off and it still makes the noise. Any ideas?? I've had the bike for three years and usually I'm told its just a Harley. The noise is happening more often.