The Stovebolt Site Forums The Shop Area Driveline Wiggling Spedometer

Hi all. What would most likely cause the speedo needle to wiggle. It will go up to about 30mph then back to 25 mph. Back and forth all the time. 30 is the about the max the speedo will go. Put a new speedo in and still have the same issue.
Its a '41 1 1/2 ton 4 speed

Thanks

Andy

Have you replaced or at least lubricated the speedo cable.
It sounds like to it is starting to bind or separate.

How do you lube the whole cable?

You have to pull out the inner cable, properly from the top or speedo head. Then clean and use a light grease, but not to thick. Wipe off all excess and reinstall cable, hook up and hope that helps. root

I'm assuming graphite would work for this

AC Delco General Purpose Lubricant

AC TYPE ST-800

AC NO.25033356

What I used in dealerships to lube speedometer cables.
Jeffrey

I like to pull the inner cable out and check for breaks then dust inner cable with graphite or teflon lube. And funnel the same lube down the outer housing.

I agree with Yuma. Binding...maybe like part of the cable has separated and is catching the sleeve as it rotates.
Jon

Mine did/ does the exact same thing, except but it has an obnoxiously loud screeching noise. The cable was NOS & I lubed it when I put it on but it didn't really work, I have no idea whats wrong with it either

What did you lube it with?

Did you also replace the cable housing or just the cable?

If cable is new and lubricated then tip seating is next possible noise issue. I have seen new cable not go in far enough to get the "notch in to the slot". Remove the speedometer end and drive seeing is squeal exists and watch the tip spin to see if it is smooth.
This is where a test speedometer or hand mechanical tach is handy for looking at the cable operation.

Another test method is to disconnect the driven end from the transmission and use a drive adapter or old gear section chucked up in a variable speed drill. You can spin it up till noise starts and stethoscope it out.

Between a drill and hand tach you can test each of the three parts to figure out where the issue is.

I pulled out the cable and there is no damage to it. The cable comes into the cab rather high up on the firewall, is this where it is supposed to come in? I'm thinking it may be binding, its a rather sharp bend

The bend should not be a sharp one. It should be a gentle bend entering a grommet on the firewall about 9 inches or so from the hood line. You could be on the right track with this idea. It is binding and releasing somewhere. This is what will cause the needle bouncing.
Jon

The cable housing has a habit of developing sticky spots due to wear of the coiled steel used to make the housing. Replacement of the entire cable/housing assembly is the only option if lubing the inner cable doesn't solve the noise or jittery needle.
Jerry