I was looking into why the speedo needle on my 72 Dart was just jumping all over the place. I pulled the cluster and discovered the plastic clip that goes to the back of the speedo head was cracked and seperated from the casing.
I have gone round and round with this mess.I ordered the cable listed for the car and the part that screws into the tranny was too small. I did research and found one that will fit out of a 69 Coronet,Its longer but otherwise it its a match to the old one. So I go through all the trouble to pull the cluster,drop the steering column,reinstall the new speedo cable Ive ordered,button everything back up,take it for a drive and the darn needle is still jumping around the same as before.
I went through all that ...and these are the results. I know this stuff happens at times,but this is ridiculous. Humor me...Was I supposed to lube the cable prior to installation? Being that the cable is brand new,I didnt think it was necessary.
What else could the problem be,could it be in the speedo head or in the gear in the tranny? Where else can I look to remedy this issue? Could fluid level have anything to do with it (3 speed Manual)
When the head starts binding up, the cable acts like a spring and winds up to the point that it overcomes the 'stickiness' in the head. Then the speedometer jumps, the cable unwinds, and the whole cycle begins again. Might try taking the head out and using one of the spray lubes on it.