Wonky Speedometer in '67 C10

[Smitty550]

The speedometer in my '67 C10 (250CID with TH350 transmission; stock gauges) seems to have developed a "bounce" that appears mostly during the first ten or fifteen miles or so, after which time it starts to operate smoothly.

I would imagine that the cable needs lubing or replacement, or maybe the problem is in the speedometer gauge itself, or maybe at the transmission end.

Should I just bite the bullet and change out the cable for a new one? If I choose this route, should I lube the speedo gauge while I'm at it? Any good videos available on how to solve the problem? Any advice would be appreciated.

Thanks,

Smitty