Our GTP was making the loud humming whining I mean like the supercharger sound and rough shifting, looked like classic pressure control solenoid. I told my family but people still drove it anyway without fixing it, and now it always whines when driving it sound like it gonna explode almost, but it never does. Not sure if overdrive is working.

Just curious, did it ruin the transmission or is it still just a matter of switching a PCS or valve body?