My 2010 Boxxer team is making an odd knocking sound with I shake the fork up and down (not side to side). Their isnt any movement in the fork at the top of the travel that would suggest the spring is moving or a lack of spacers and the fork is still performing wonderfully so I wouldn't know if there was a damper issue or anything. Before I take it apart I'd like to have a rough idea of where I should be looking. Is it possible the drop-stop is just moving a little bit inside the spring side? Any solutions?