Trans will not go into OD

[BIG B]

The OD light is flashing so I look under the truck and see the speed sensor? hanging down. I guess it is broke? I am not sure. The speedo does not work either. It shifts fine in the gears but no over drive. Any sugestions and how much are those sensors? I have a 1996 sport 4.0 4x4 auto THX

 

[BIG B]

Ne1?

 

[toy720]

which sensor are you talking about the one at the very rear of the transfer case
little black one? that is the only one that has anything to do with spped besides the one inside the trans on the center support.