Odometer

Likely they're done and need to be replaced. These things are all electronic now, and even though it looks like an analog gauge, it is just a dial output. Everything pretty much runs from the onboard computer so it should be a relatively easy repair to change out that component.

 

I have a 98 4964FX. My odometer would work,but would jump back to the original reading when I shut it off. I purchased a new speedometer/odometer from WS and it fixed the problem. You have to start from zero with the new unit, as you cannot set it to the correct mileage. I had the dealer plug in to the ecm and get me the correct mileage which I add to the mileage on the display to get the correct total.