So my Speedometer on my 67 quit working, when it started acting up it would go up to about 20mph no matter how fast I was going and just stay there, then a couple days later it just wouldn't do anything. So I figured it was the speedometer cable and I changed it out, but it still doesn't work. Has anyone ever came accross anything like this? I'm wondering if it's the speedometer itself or something on the other end. Thanks...

 

Take the cable off the transmission, have someone watch the speedo and turn the cable with your fingers. With a quick spin you should get the speedo needle to move. If it does not move, make sure the cable is inserted into the back of the speedo, too short of a cable won't spin the speedo. If it does, pull the drive adapter from the trans. One bolt holds it in. From there you can check the driven gear which is plastic.