Hi Doug. Intermittent operation of the odometers usually indicates that a gear in the side of the speedo head is hanging up on a piece of junk--usually a piece of the gear! However if the speedo itself is also coming and going, it indicates something electrical. It would be unusual for something to physically be binding both the speedo movement and the odo drive.

Normally I would replace the side board on such a speedo head (or swap out the head completely). If you have the patience, you might try resoldering all the points on the side board. There are a bunch of them and it's tedious work. If you have the equipment you can check the capacitors on the side board too. I've only "saved" one board in several years by replacing a cap, but they can be the problem.

One more thing you should check: The angle plug on the back of the cluster that attaches to the speedo head board--make sure all three pinch connectors are tight. Check the area on the board where the plug attaches for fractures. If one of the contact patches where the plug slides on is cracked...well, you can guess. Check the ground wires for good continuity to ground.

DS