Odometer not working and needle bouncing. Should I by a new one or have the original serviced? Who would i send it to?

 

have you tried pulling down on the odometer reset ****? have you tried carefully lubricating the cable, dont get any into the speedo head, with a graphite based lube?

 

On any speedometer.. 1953-1977....

If the needle sweeps wildly and breaks..... or.....
If the odometer is not working and the needle is then speedometer needs to come out and be serviced. This failure has nothing to do with the speedometer cable it has to do with the first worm and magnet inside the speedometer.

When the first worm bushing wears out.. it puts the first worm A in a bind with the second worm B. The first, second, third and fourth gears are what drive the odometer and the trip odometer and once A is in a bind with B it will eat itself up.

Once the bushing gets worn enough the first worm magnet will start hitting (scrapping) the speed cup... The speed cup has the shaft the needle attaches to once the first worm catches the speed cup it will slam it breaking the needle.

If you have a odometer not working, replacing (and they are available) the second worm gear with the plastic replacement is only a band-aide and actually a huge waste of time considering how hard it is to remove the speedometer from the car.

If the odo is not working and the speedo is jerky, odds are you're going to need the complete speedo head rebuilt to correct the issue and if you are not prepared to do this then uscrew he speedo cable. Leaving it alone will just do more damage to the existing parts.

I'd also like to remind everyone to NEVER put grease, wd-40 or other types of grease (lube) on a speedo cable. The cables are reverse wound and this will pack the grease in the speedo head.. The first worm bushing is made from oylite and the lube will cause premature failure. If your cable does need lube, only use the appropriate lube.

https://willcoxcorvette.com/corvette...ble-lube-53-08 I've pasted below this the AC Delco page from our calibration book on this procedure.


If you want to get the speedo out of the car, here is the easiest way.
Willcox Corvette 1968-1977 Corvette Left Hand Dash Pad Removal The Easy Way Click on supporting document once there.

Willcox

 

I have mine apart to replace the odo gear. The bushing looks fine. I didn't pay enough attention to the speed cup when I took it out. It is up against the zero stop in this picture. Does it look like the gold spring is wound enough? I'm concerned that I might have jumped over the stop and I let it rotate a full turn counter clock-wise, which I believe will make the speed inaccurate. I assume the spring tension needs to be right to offset the speed cup pull for the speed to be correct.

 

Might want to start an new thread...this one is 10 years old.

 

Responding to a post in a thread after 10 years; might be time for a new thread.