If you are referring to the gear indicator and mileage in the center of the gauge cluster, it is common issue for the solder joints on that display to go out.
I searched and found several threads on it... But none that give much info. It seems the only fix is to rip apart the cluster and resolder bad joints or get a new cluster/repair.
Many places on the internet offer repair service or refurbished units. Search the Internet and eBay to find. Digital Dash Solutions seems to be big into it. Good thing about a place like that is you get all new motors, an added transmission temp gauge for 03-06 and you can get different needle colors.