I had a pop after I first installed my Zone disco's. I tried to ignore it for a couple weeks because it sounded expensive and I really didn't want to know. My pop was the disco's. I really should have connected the symptom to the disco's. Mine were tight, but the upper bracket was slightly turned. Lined it up better and it's all happy again.
Hope yours is that simple a fix. That trail did suck, didn't it? My back is still hurting. Sent you an email too.
The most complete guide to Southern Nevada historic mining.