New speedo cable craziness

[Slysdexia]

Okay, so the original speedo cable in the truck (at least when we got it) had come in contact with the exhaust manifold, melted, seized, and then broken. Odometer says 127k, but there's no telling how accurate that really is.

Anyway, got the new cable in, and a new driven gear, and the speedo is fine to 50 now (was only good to 35 at first) but then starts going nuts until I reduce speed below this threshold. Is this normal wear-in behavior for a new cable?

 

[Big Jim M]

Used to be when them cables got a BEND in them or some RUST in them or even a LACK of grease the speedo needle would jump around. Is there an obvious bend that could be straightned out? Does it have a permanent kink in the thing?
The inside cable should turn at even speeds to make the needle behave. If the cable slows and then jumps ahead and then slows this causes the needle to go insane.
Big JIm