I have a '97 Mustang Cobra and I have been noticing a loud popping noise around the rear end/driveshaft area. It only happens every once in a while, through up to 4th gear. I was thinking maybe it was U-joints but I'm not sure. Any ideas? Thank you. By the way, I've heard that I will not be able to change u-joints myself. Something about I need to put them in a bearing press. I don't want to spend the ungodly amount of money to have the shops fix it. Any suggestions?