1998 CHEVY SILVERADO SHIFTED FINE LAST NIGHT TODAY IT WONT SHIFT FROM FIRST
on 1998 Chevrolet 1500 Pickup

350 AUTOMATIC TRANS.

1 answer
In case you haven't figured it out yet, it's probably the Speed Sensor located at the back of the transmission, on the side - I think on the driver's side. Unplug it and I believe one bolt holds it in.
Auto Zone has them for $23.