Speedometer whacky with Tranny problem

96 Ford Explorer that I had the transmission rebuilt 2 months ago from a shop I have had good quality work done for years. Yesterday, the speedometer started going completely whacky (spiking up, needle not moving at all, reading incorrectly, etc.) Now the vehicle won’t even shift through the gears (3 speed auto tranny) and runs terrible. Any suggestions ??

Check Engine light on? Sounds like a bad VSS (Vehicle Speed Sensor), since the transmission controller uses it to determine when to shift. See if the trans shop can help you.

Yes, forgot to mention that the check engine light did come on. The vehicle is back at the Tranny shop now.