The transducer is done for. Replacing the cable will only twist the end off the new cable. The transducers get moisture in them, and rust up, and the grease used on the gears gets hard/gummy. That is what causes the thing to lock up, or get so hard to turn that it twists the end off the cable.
You can get a cable to go directly from the trans to the speedo head, but then you wont have cruize.
So...either replace the transducer, or do without cruise. You might find a place nearby that rebuilds the transducers, but those places are few and far between.
______________
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"