91 explorer tranny problems?
 

i was turning onto a highway n my 91explorer jus stopped excelorating but the rpms kept runnin up. it will start but it jus wont go into gear. wen it quit it jus kinda clicked but it wasnt loud at all. but now wen u turn it over it has a slight whine to it. my dad is set on it bein the torque converter, my buddy is leanin towards the valve body or the shift motor. the 4wd has never worked. n wen u have the truck in park u cant push it forward or backward. any thoughts cuz i really dont feel like dumpin a bunch of money into this thing n jus b huntin n peckin tryin to find the problem