Speedometer Reading

[Ralph Messina CLC 4937]

I need some diagnostic help with speedometer reading. When I purchased the car -66 Eldorado- the speedometer worked, albeit with some needle indicator shake with body motion. After rebuilding the car I never checked the speedometer reading because the Cruise Control was not attached. I eventually opened and inpected / cleaned the unit and installed it. The speedometer now works fine up to 40MPH but will not go any higher.  All the visible connections are correct and fit properly.   I’d appreciate any suggestions as to the cause or likely place to start looking for the problem.

Thanks,
Ralph

[The Tassie Devil(le)]

G'day Ralph,

Firstly, does the Odometer operate at all speeds?

If so, then the problem is going to be in the swinging arc of the speedo needle.

The Odometer and the Needle aren't physically joined together, so if one is working, and the other not, then it is in the actual speedo head where the problem lies.

Bruce.