I think my alternator is about to die. When i come to a stop and im still in drive (have breaks on) i heard a strange sound kinda of a low rattle. I figured something was loose so i looked in my engine compartment and saw my alternator shaking violently. I checked to make sure it was mounted firmly and it is. Whats going on? Is my alternator about to go? Its been getting louder lately... If my alternator is about to go i figured i would go ahead and upgrade. I plan on running a winch and dual batteries in the near future. How much more power do i need? Is mean green in my future? I dont want any crappy chevy products under my hood so you can rule out any gm parts.