I had a similar problem on my 2006 magnum 330. I blew out my belt...
But when I went to put the new belt on, it seemed overly loose and it hit the cover as well. So I found this thread and after rigging myself up a nice spring compressor to get the c-clip off the back of the secondary I found a huge amount of belt dust and abnormal wear on these so called "buttons" and a bit of wear on the helix riders as well. I ordered new buttons and a new spring, just because I'm here, after its all back together ill fine tune the belt tension via the washers behind the secondary, I have 4 back there currently so I have some room for adjustment. Here's a pic of one of the buttons
Ill let you know how it all goes when I get it all back together!
Thanks for all the tips and insight, always appreciated.