Speedo issues
A lot of the problems associated with speedometers are usually due to cables being dirty,bent, or broken. The cable should be removed and both the cable and housing should be thoroughly cleaned and the cable greased and reinstalled. Check to make sure the housing is good and that both ends are connected well. If that doesn`t solve the problem,try the HELP section at your local auto parts store, they should have a new cut to length cable. HTH.