might partly be the mechanism where the cable plugs into the speedo is gummed up, but I'd bet the cable needs replacing - have you pulled the inner part of the cable right out of the housing? it should NOT be lubed w/ oil, but cleaned and dried well and treated w/ dry graphite - if you take it right out and get it clean you may see places with wear marks, or some of the stranding may be messed up - the whole cable isn't that expensive, and you can find one [a "universal" at least] at an auto parts store
Bill
