stuck speedometer

GM may pay for your repair it has a 7 year warranty & 70,000 mile. If you had the work done ask them to cover your cost!

It sounds like your Speedo/Cluster is malfunctioning, which is some what common on these vehicles. I would have your Cluster scanned and properly Diagnosed. If it does not do the 'sweep test' when you first start you vehicle( ALL needles go from the minimum to the maximum and then minimum in a second or less ) then you do have an issue with your cluster.

I have the same issue with my 2004 Tahoe. I found by starting the vehicle, droping into 1st gear and turn the engine off. Go back to park and restart the vehicle. It resetes the odometer to -0-,It is a temporary fix that may last only after driving the vehicle a couiple of times, but cheaper than $700 to replace the darn thing. Get a gps and keep it in the vehicle for a back up on mph, cheaper than a ticket also!