I'm having speedometer problems with my 2003 Avalanche with the guage reading too fast ( 75 when I'm going 25 ) or too slow ( 10 when I'm going 50+ ) or no reading at all. I did a google search on speedometer problems and found a web site - Topix.net, about the only way to find the speedometer postings from the over 180+ of us is to google search speedometer problems with chevy trucks and you will find it. If your having problems with your trucks speedo, go there and read the postings and file a formal complaint with the NHTSA. GM hasn't put out a recall as of yet.
My dad has a 2004 Silverado 2500HD Duramax diesel and the speedometer stopped working completely. We had a extened warranty so it was no charge but I am pretty sure they did a recall on it so anyone could get it fixed for free.
i have a 2003 avalanche got my speedo fixed from a guy on ebay 148.00. shortly after that i received a letter from chevrolet that they are fixing the problem for free
