There is an "ABS Differential Sensor" on top of the rear differential that controls your speedometer. Napa part number UP 530778 or UP 530846. take the old one in with you to make sure you get the right one. i believe there are 2 pin and 3 pin versions.
FYI, the one you replaced on the transmission is for the powertrain control module. that's the one monitored to set your shift points, and i believe, to determine weather you are at a safe speed to shift in and out of 4wd.
Is the TCM working normally and throwing no codes?
May have replaced the wrong sensor or you have a bad wire in that curcuit. gm Jim
Since you replaced the sensor, and the speedometer still isn't working it is possible that you will need to replace the speedometer cable. Check the cable first to be sure that it is still properly connected, and if so replace the cable to see if that solves the problem.
Bad wheel speed sensor or cluster needs replaced
The speed sensor needs replaced. It is on the trans.
Has just the sensor been replaced or the plastic drive gear in the trans as well The drive gear often wears uneven causing the speedo to go inop
If an input output sensor has gone out, it will affect the functionality of your speedometer. If only the input sensor is affected, the speedometer will work with limited functionality. The output sensor will cease the speedometer from working completely.
There is no speedometer cable. MPH is calibrated using a speed sensor. If your speedometer is not working, you have a bad speed sensor module.
You may need to replace the speedometer fuse. The speedometer cable can cause your speedometer to stop working. The speed sensor can also cause the speedometer to stop working.
We had the same problem, and our 1998 F150 needed a new instrument cluster.
could be the speedo cable?
you need to change the speedometer cause if your odometer is counting then speedometer should be working too. make sure your speed gear its working its in the side of the transmission The odometer and speedometer read off of the same signal. If one works, the signal is ok and the other gauge is bad.