bad odometer/speedo after tranny fluid change

[daredevil350]

In theory your problem is possible, the speedo is a magnetic/electric sensor rather than actual gears. So if you have an open wire/sensor you could see this problem, fluid level will not affect this though. Check your wires for any obvious faults, check the sensor, disconnect the battery for awhile. Pull the speedo sensor out of the drivers side of tranny, 10 mm bolt, clean it and re-install.

[robertfoster]

Does the needle drop back to zero if you hold the engine speed at 1500 or 2000 rpm?