James,
If you are having problems with you cruise control, as you indicated, I would suspect that it is NOT the cable.
Do you have a vibration when you coast at highway speeds? If so, your problem, as I previously posted, is the output flange nut at the transfer case.
Drop the front drive shaft from the transfer case and you will see a bolt inside of the flange. Tighten this bolt to 280 foot pounds and this will fix the vibration, cruise control and the speedometer jumping!
Ford has a TSB on this repair as well. If you are interested in the TSB repair, e-mail me directly and I will forwarded you a copy via e-mail.
Doug