Transmission wont shift to 3 & 4 gear

PLease help I have a 96 Lumina and recently it was hit on the drivers side by a trailer tire (The rim broke and I was the afortunate one to get on the way), the car was "fix" but now the transmission wont shift to 3rt and 4rt gear looks like 1st & 2nd gear is OK. Any help is geatly apreciated.

Look at the line on the trans modulator, also make sure the main harness plug to the trans is tight and clean in the connectors. After that have it scanned on a trans scanner for tps and shift solenoid functions.

I forgot to mention that the speedometer is not working eater at all (stays at zero)

The key to the problem, no speedo the trans is in default, have the VSS and wiring checked, most likely the problem.

Where is the Vehicle Speed Sensor located?

In the trans.

I will trobleshoot it this weekend and see if I can get to the problem, Thanks for your help.