I have a 2000 GMC Sierra and had the same problem. It is very annoying and I would guess a dangerous condition. As someone stated above, there was several service bulletins out on these trucks about the intermediate steering shaft (the shaft that goes through the firewall.....connects steering wheel and underhood parts of shaft). It is covered under a service bulletin so fixing your truck can be no cost to you. However, if like me, I couldnt afford leaving my vehicle at the dealer for a day. I payed around $15 for the grease kit and did the work myself. It only took about 15 minutes and was very very easy to do....only 2 bolts. It always sounded weird to me that all this thing needed was some grease........but hey mine dont pop anymore! Hope this helps