The Stovebolt Site Forums The Shop Area Interiors Bouncing speedometer needle and odometer does not advance

hi.

out of nowhere the speedometer needle now bounces around 20 mph plus and 20mph minus of what the real speed is.

so, if I am going around 40mph, the speedometer bounces between 20mph and 60mph (more or less)

and the odometer no longer advances.

where should I start to try and find out what is wrong - since this worked fine for months.

thanks in advance