Cliff
I had to take mine apart and found the odometer/ drive gear had a bad spot. It was plastic.I swapped the brass parts from an Ebay gage cluster I bought ~$35 if I remember. It was tedious but do-able. Like was said... the odometer wheels are sensitive I ripped some #'s off but replacement decals are available. Once apart I bet you'll find the trouble.
John
Still driving Dad's '59