Speedometer issue

[Car #4]

This is on a 68 Charger that I bought a year ago and I don't have much history on the car. One day last the speedo jumped up to about 100 and stayed there. A few outings later it moved to 70 and stayed then later it went to 150. It never came back to zero at any time. I knew the speedo was inaccurate from the beginning so this winter I checked the gear in the tranny and it was way wrong. I got the right gear and put it in and when I was done all this the speedo needle was back at zero. On Sunday I took the car out for a run and needle didn't move for a while and then it went to about 10. Then all of a sudden it went to 150 and stayed there. Through all of this the odometer has kept working. The odometer has about 1500 in it and I believe the speedo cable was new at the same time. When I had the cable off the tranny I could roll it very easily between my fingers, there were no sticky spots.
What's going on here? Sorry for the long winded explanation.

 

[Demonic]

Sounds like the speedometer itself is bad. If you have a road with mile markers - and the odometer is close, it's the speedometer. Lots of places still fix them.

https://www.bobsspeedometer.com/1/120/index.asp

 

[dan juhasz]

The problem is in the speedo head itself, and I wouldn't be shocked if the head just needs to be cleaned and get a drop of light lubrication

 

[Car #4]

The speedometer is new. It shouldn't need cleaning and lubing should it?

 

[493 Mike]

The speedometer is new. It shouldn't need cleaning and lubing should it?

No. It's broken.
Mike

 

[69Bee]

Also make sure that the speedo adapter is properly aligned for the number of teeth on the gear.

 

[dan juhasz]

The speedometer is new. It shouldn't need cleaning and lubing should it?

New repop?
It’s broken , perhaps damaged in shipping. Very delicate