Broken speedometer cable. I took part of the cable, inserted it into the back of the speedometer, and tried to spin it with my fingers. I assume it should be easy to spin. I can't get it to move. It seems odd to me that a locked up speedometer would cause the cable to twist off without causing the speedometer to disintegrate inside and just free wheel. Is it possible to just replace the speedometer? It looks like there is a cover held on by four screws, but not sure if the speedometer would come out after taking that cover off. Anyone familiar with this speedometer replacement? Thanks. TommyJ