I have a 55 2nd series Chevy. When I bought the truck the speedo cable was broken. When I was redoing the interior I removed the gauge cluster, blew the dust out of it and tested the speedo with a drill. It worked fine up to 30 mph (that is all the faster the drill would turn it). A few months later I bought a new cable and lubed it lightly with a white grease stick. After installing the cluster I took it for a test drive and the speedo needle was jumping wildly below about 30 mph and over 30 mph it would peg over to the 100 mph side and squeal a constant squeal.
I removed the cable and oiled it with a light Teflon oil and re routed the cable to make sure there were no sharp bends in the cable but the problem remains.
So the question is that I have is this...Is it a problem with the cable lube or the speedo head its self? BTW the odometer dosn't appear to be working correctly either.

Thanks.