I’ve noticed my 94 lightning here lately has the speedometer needle jumping. It’s not real bad just a twitch and on the bad days it will jump off zero while making a complete stop. How do I fix this? I’m thinking a new speedometer cable? Or are there trucks digital?

　

Thanks…

 

It's likely that the speed sensor is either dirty or it's going bad. It is mounted on top of the rear differential, pull it and clean first to see if that helps.