Join Date: Mar 2002
Location: Austin, TX, USA
Usually the cable gets bent or dry as Dave suggested. You should probably also disconnect the speedo cable from the tranny and look at the opening where the cable inserts. The speedo gear is plastic and sometimes the gear gets "wollered" (that is a work isn't it) out. But usually that is caused by a hang up of somesort in the cable.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI