I have the same problem--jumpy below ~30-40 mph and then solid as a rock above. My speedo's pretty accurate (within 5 mph) once it settles down. I bought the sensor last year but haven't yet installed it.
How difficult was it? It just bolts onto the outside of the transmission? If it penetrates the transmission case, any concerns about fluid leakage when replacing it?
Sorry for the dumb questions.
Thanks,
David
