I have an old analog mechanical speedometer in my car that makes noise when I start driving my car. The faster I go, the more noise it makes. Is it repairable or do I have to replace it? I have found another used speedometer on Ebay but this one has less miles. How do I set it to the correct mileage?
How old are you talking? Do you have a speedometer cable? The speedometer cable could be binding up and causing it to make noise, but that can also cause the needle to go around randomly. Pull your cluster and put a drill with a flathead bit in the slot where the cable goes and gently spin the drill. If the noise goes away and it moves smoothly, the speedometer cable is probably shot. My 1979 Catalina has either a bad speedometer or cable. It clicks and goes all over the place, and the behavior doesn't really improve when it's out of the car. You can send those old units off to be repaired for around $250.
Chances are it's the speedometer cable binding up and it needs to be lubed or replaced. (There is cable lube available, usually graphite-based.) As @justin-shepard says there are places that can rebuild your speedometer head if that's the source of the noise.
My Catalina's instrument cluster clock doesn't work, either. I've read GM cut corners making them and they broke easily -sign of things to come, 40 years in advance? Haha. I was quoted $250 for the speedometer rebuild and then whatever else my clock needs.
You can have the clock converted to quartz electronic movement if you like. (Assuming it isn't already that type. AMC was installing quartz clocks starting in 1979, not sure about GM.) Will last a lot longer than the electric-winding mechanical type but you lose the mechanical "tick-tock". Check Hemmings.
My old truck did the same thing and I disconnected the cable from the back of the speedo and lubricated it and it works fine now. If you need a rebuild, United Speedometer in Riverside, CA is one place I know of.
