I am not an expert on these but I have played with some of my spares. The input shaft and the needle shaft and mechanism are concentric. There are bearings that take the thrust and keep the two functions separate. On one of my units, I believe pushing in on the area where the cable drive goes in will apply torque directly to the output indicator shaft. That sounds like what happened to your when you were driving. If that is the case, some of the bushings or bearings are worn out.
Last edited by truckernix; 04/16/2014 12:51 AM.
