One problem related to steering rack and pinion has been reported for the 2004 GMC Sierra. The most recently reported issues are listed below.
Contact states since 7-04 had steering problems. In 3-05 he received a letter from GMC stating that they extended the warranty to 2-11 or 100,000 miles because of all of the problems he had been having with the car. His warranty was about to run out and he was still having the same problems with his truck. He was going to forward other pertinent documents later concerning the numerous repair work he has done.