2003 Yukon XL 4x4 Pop clunk issue

[prettytwisted]

Hello, I have a 2003 GMC Yukon XL 4x4 and I'm having a issue where it still runs and will drive but when I put it in drive and get ready to push gas to go instead of it being easy to go you have to press gas pedal down almost to floor for it to move any and when it moves it makes a loud clank and pop like something catching underneath the vehicle . We have been trying to figure out the issue for months it broke down on is coming down high way heard a metal on metal noise stopped and pulled over to look and then went to go again and it was doing same as I said above and we had to have it towed home please help us get back on the road thanks

 

[Scottydoggs]

get the back wheels off the ground trans in neutral, spin the back wheels by hand, listen for where the clunks are coming from. i'd suspect rear end or transfer case. maybe even the transmission.