the odometer in my car has never worked,although the speedo does, I`m sure someone once told me that it was a gear that moves to one side so is no longer driven
There driven by a set of small plastic gears and shafts, mine had siezed up , stripped it and sprayed it all with WD 40. Gave the odometer numbers a spray and worked them loose. Now seem ok.
a job for over winter!!