One problem related to steering tie rod assembly has been reported for the 2007 GMC W Series. The most recently reported issues are listed below.
At highway speed, any slight bump in road may cause the vehicle to start violently shaking. I have heard it referenced as a "death wobble" and that is so accurate. I have replaced almost everything - tires, shocks, tie rod assembly, toe-in set, etc. Problem still occurs. Problem doesn't happen daily - but it happens suddenly and is frightening. This is a box truck carrying a load and when the violent shaking occurs , you have to hold tightly to the wheel and try to control the vehicle from highway speed 55 - 70mph down to about 30mph before the shaking will stop. This is a serious issue that the manufacturer must address!.