If any ones still wondering about this im pretty sure mine was coming from my rear end. It tried to bind up when i took off from a stop light when i took the rear diff. cover off i found a bunch of ground up metal, almost two hole teeth and a barring carrier. I'm geussing a bearing whent out and just aight up my ring and pinion i havent been able to taer it down yet so i dont know which barring it is or if that was the shutter.

 

I have a 2007 4x4 with 90,000 miles and it started doing the same thing this week while i was at work. Then yesterday it started running like crap and threw a couple of faults saying misfire on cylinder 2 going to replace coil in a little while hope that fixes it