This last week my truck started making a chadder type of noise on rough roads, and a slight vibration at higher RPMs. It turned out to be the two bolts on the trans mount had sheared. I was at a friends shop when we found it. It turned out to be an easy fix. The sheared bolts came out easy with just my fingers. Two new bolts, and 30 minutes later I was back on the road making smoke. 
