Oldsmobile/Buick Repair: speedometer, vehicle speed sensor, tail shaft

Question
I have 1999 olds bravada, i have replace the transmission and now the speedometer doesn't work and will not shift from 3-4, i found the speed control sensor on the transfer and switched with the one on the tail shaft no difference,could they both be bad also the cabs light now flashes.

Answer
Hi
was the speedo working before the trans replaced?
If so, then I really doubt the sensors at fault.
I would advice you to take it to a repair shop, and see if the VSS (vehicle speed sensor) is sending a signal to the PCM.
If so, it MAY be your cluster.
If not, check the wiring and the sensors.
Hope this helps
PAwl