Speedometer all of a sudden reads way too fast.

I left a man sit a couple of
months and now the
speedometer reads way too
fast and when you're going
about 30 mph it says 100
and the speed limiter kicks in
and slows you down a little
bit and then comes back on I
have changed the speed
sensor in the transmission
and also had the
transmission rebuilt about
30,000 mi ago it worked
perfect. Up until this point.