It jumps around 10-20mph. The noise (grinding dry speedo cable type) came in right after I re installed the cluster. I had pulled it to unwire the ammeter and install a solid state cluster voltage regulator and capacitor.
I may be stuck on the wrong track here, but as I stated in my other thread, the fact that the noise came in right after removing the cluster suggests to me that it is not the cable. It bolted back in with no problem, no binding or anything. I even pulled the cable and lubbed with wd-40. However, that didnt even make a dent in the noise. no change or anything.
The jumping is much worse now, however, even when I was a little kid riding in this car with my grandfather, I always remember seeing the speedometer jump around. Although if I had to venture a guess I'd say it moved maybe 5-7mph.