"Is your speedometer steady or does jump some when this happens? "

It's funny you posted this question, because I *just* thought of something I had forgotten because it hasn't happened in quite a while...but a few times last year the speedometer did jump around, gittering back and forth and sometimes pegging out at either the highest or lowest spot. I know it hasn't happened lately though, because what attracted my attention when it DID happen was that it made a distinct clicking sound when it was jumping around.