I have a 69 Camaro, we went for a ride and the speedometer was working when we left. A little while later it quit. I pulled the cable and it works when I spin it, pulled the gear out of transmission and it is good. put it back together and speedo is working. could the speedo have an issue (working-not working then working)?

 

It could be the speedo but a more common issue would be cable wear. The outer housing will get wear and allow the cable to fall out of the Speedo. I have even seen it were it only fell out when hot as the outer cable expands.