The Stovebolt Site Forums The Shop Area Driveline Unexpected speedometer issue

My speedometer on my 54 3100 3 speed has not worked since I got it 3 years ago. It was a low priority on the list of things I needed to do. I finally got around to working on it. I always suspected the gears at the transmission were broken. Early on I was able to connect a drill to the speedometer cable and make the speedometer move. I pulled the gear from the transmission, Just the one the cable engages with, not the one in the transmission. It looks good. I then noticed the hole the cable plugs into didn't look right. I then realized it was enlarged and worn out. I suspect that at some time over the years the cable had rusted/frozen and when the truck was move something had to give somewhere.

Do I have any options to repair what I have? My first thought was to clean out the receiving whole and fill it with epoxy and then insert a cable end coated with Vaseline or some lubricant the epoxy would not stick to. In other words, a mold for the epoxy to conform to and reconstructing the receiver.

I realize this is probably not going to be a strong enough or permanent fix, or would it?

Any suggestions are welcome.

If I need to replace it how do I take it apart? I did not spend a lot of time examining it but the plastic gear does not just pull out of the metal house that screws into the side of the transmission, Can I source that piece anywhere and reuse my plastic gear? From what I have read it can be difficult to find a replacement gear. Do I need to find an original somewhere?

I had the same issue, and tried the epoxy, JB weld, fix. It didn't last long.
I got a replacement gear from someone here , just post a parts wanted.
I don't know how you got a plastic gear in the mix, the originals are all metal. I haven't seen any catalogue vendor replacements that are exact duplicates....anyone?

It might not be plastic. I was remembering the gear from my 72 Olds 88. I need to pull it back out and get a better look and some pics so I can search for a replacement.

The square hole in the speedo that accepts the square end of the cable had rounded somewhat. I made a wooden shim from a flat toothpick and the speedo now works correctly.

Toothpicks are so awesome. Not only can they pick food out from between your teeth............

If it's plastic, it's probably nylon. Can't you simply melt some plastic into the hole with a soldering iron? I've found with the iron, you can get the 2 plastics to "merge" better. Then heat the end of the cable just enough to create the (square) shape you need in the gear. If all else fails, you were looking for a new one anyway. My experience(s) with replacements have always been a kit that included the cable, as well as the gear.

Good luck!

Chris

Dave,
I had the opportunity to use this place this summer. He helped me with making an extension for my cable.
Rusty, the owner has an old time shop and can most likely help you.
https://www.speedoservice.com/