Speedometer trouble

[knutsoe28]

71 demon. Speedometer stops at 50 mph. I can be going 75 down the interstate but needle will stop and peg out at 50 mph. Any suggestions on the problem. I would suspect the cable but not sure.

 

[TrailBeast]

It is very slightly possible the cable is slipping at one end or the other but I seriously doubt it.
WAY more likely that the speedo head is dirty and resistance where the needle pivots is to high for the magnetic drive that the cable turns to overcome.

 

[trapster]

Needle is probably hitting the face of the dial

 

[knutsoe28]

Thanks guys.