Bad rearend
 

Hey guys !! And girls if any..lol.. I have a 2003 Chevy Z71 silverado ext cab LS 4x4. Something snapped in the rearend pumpkin. Does anyone have an idea what it might be and is it repairable?? Or just buy a used one? The truck is moveable but it clanks as soon as it shifts out of first gear. I don't think it's quadrasteer. I called about a used rearend and they asked me that. I don't know how to tell. Thanks for the input :)