After leaving the inspection station the other day (ironic I know), my speedometer quit working on me. I pulled the gauge cluster and spun the back of the speedo and the needle moves so that's good. I drove the car with the cable disconnected from the speedo and it wasn't spinning. I inspected the cable and it had melted pretty bad from being near the headers. Replaced it and left for a photoshoot with the car and speedo still wasn't working. I'm guessing that the nylon gears in the trans must be shot? They only have about 12k on them so I find this hard to believe. Is there any other mechanism in the trans that can go bad besides the nylon gears themselves? If just the pullout gear on the side is bad should I still replace both? I'd rather not pull the tailshaft but it's not the end of the world if I have to replace both gears.

 

I'd pull the speedo cable housing off of the tail shaft, inspect the gear and have a look at the nylon gear inside at the same time. Hopefully it'll be something as simple as a driven gear replacement.

 

Found my problem last night. After pulling the driven gear out and trying a few tests with it I realized that the old cable had broken, just not in the middle where I had thought. The old speedo cable actually broke all the way at the end right where the square drive fitting is crimped onto the wire. I found the old end piece still stuck in the driven gear setup in the trans. A dental pick pulled it out and I was on my way with a working speedo again.