Most common would be speedometer cable has broken Remove speedometer head and move vehicle to see if cable moves- if not probably broken - if it does probably problem with speedometer head
Either the Speedometer itself is bad or the speedometer cable is. either one isn't too difficult if you have pulled a dashboard out before.
its old
check fuses
possibly a broken internal gear in the speedometer head
Replace the fuse.
i would have to bet on the speed sensor
The speedometer itself will work but you will need to take the instrument cluster apart and transplant the speedometer unit from the 92 cluster into the 87 cluster. The speedo mechanism is the same but the clusters are different.
will a 3.8 engine from a2002 Camaro interchange with a1999 camaro
Vehicle Speed Sensor
If the speedometer works but the odometer does not, the odometer has failed.
NoNo
Should read "...speedometer and odometer don't work..."