Metal Chattering noise

A few weeks ago I was out cleaning up some of my property after some storms knocked out a bunch of trees. While driving along a hill side in 4x4 i starting hearing a clicking sound that would stop as soon as i took my foot off the gas.It also quit once the terrain leveled back out. Driving on the road back to the house with a load of a couple hundred pounds of brush, the chattering/grinding noise started up again while driving at any speed and persisted for the next day before quitting again. Local dealership said everything seems to check out ok and they were never able to reproduce the sound. The 4x4 still works, nothing is loose anywhere that i can tell and the drive-ability has not been impacted. What is concerning me now, is when i drive through dips in the road(usually before or after crossing paved over culvert pipe) that compresses the rear suspension i hear a brief metal chattering/grinding noise. Sound can be produced more frequently if there is weight in the rear end (200 pounds or so), so I think the source is in the rear, however I am half deaf and everything sounds like it is behind me anyway. I had my younger brother help me locate the sound and he says front right. Nothing appears to be rubbing or loose as earlier stated. And the sound will only occur when the rear compresses. I am hoping someone here can give me some ideas on where/what to look at next or what may be the cause of the sound. I have not closely examined the struts, rear shocks, leaf springs themselves yet to see if maybe while driving over the hill sides one was over extended/compressed and damaged. I know it was flexed out pretty far at one point.

Truck is a 2013 DCLB SR5 4x4 auto. 2" rear AAL with Bilstein 5125's and front has 5100's with Eibach 3" lift springs. Control arms are factory and I plan on replacing them with a stronger aftermarket arm in the next week.
Any suggestions are appreciated!
Thanks!