ya it was at the rear u joint that connects the driveline to the diff. i was driving and the truck started to shake real bad so i pulled over gave everything i thought it could be a once over, pulled off the curb onto the road and it fell, pulled back up on the curb got out and seen that my driveline was not attached anymore. luckily my buddy has a duramax and a car trailor so he picked me up and got it home and found out that it was a ujoint. $26 dollar part at napa and its good to go.