Transmision whent clunk and speedometer stoped working.
speedometer not working on 2000 Cadillac Seville SLS
Is there a Check Engine/Service Engine soon light on? If so using a scan tool will determine if the code stored is for the Vehicle Speed Sensor (VSS) on the transmission. If no light is on more diagnostic work will need too be done to see if the problem is a fuse wiring or instrument cluster issue.