Erratic speedometer on 2005 Chevrolet Silverado 2500 HD

My truck's speedometer reading is erratic. It will peg out while idling, it will start at 45 mph (for example) when cold started then eventually pegs out. On a good day it will zero out and work perfectly. Any ideas on where to start troubleshooting or do I simply need a new speedometer gauge panel? Is there a recall on this type of problem? Other than this issue, my 2005 with 24K miles is a thing of beauty!

2 answers
Your 2005 Chevrolet Silverado will most likely need to have the gauges "cluster" sent out for repair or exchange. GM has extended the warranty of some of these clusters to 80K mikes. I would recommend you see your local GM dealer to confirm this extended warranty on your gauges cluster.
This is very common on the 03-06 Silverados. The cause is the motors behind the gauges are failing, they all go out eventually. You can get it repaired here - www.drspeedometer.com and there's a DIY guide here - www.howtorepairmyinstrumentcluster.com