My van has been displaying the classic symptoms of a speed sensor
problem - service engine light, funny shifting, speedometer dead. My
mechanic has, with some difficulty, found the input and output speed
sensors and replaced them and still no go. He showed me a different
part, which he recieved as a speed sensor, and he has no idea where it
goes. Is this the ABS speed sensor, and could it cause the same
problem? He's going to crack open behind the dash next week to take a
look at the instrument cluster, but will a fault there cause the same
problem (the tranny not recieving the speed information?) Could the
speed sensors he replaced be mixed up (the output in the input and vice
versa?)

-JD