2000 24 valve auto tranny issues

[Concreteconvict420]

Having problems with tranny staying in overdrive. If and or when it does wanna shift into od as soon as I let outta the throttle it will clunk kinda hard depending on the speed when it happens it will damn near put ya in the windshield when it happens but when it first started i was in the fast lane and someone cut me off so I got outta the throttle and it was like someone reached over and pulled it down into low side so I stayed outta it for a sec then got back in it, it tached the rpms up to 2800 and it acted like it was stick in for a few min and then finally shifted since then it has gotten worse it started about a month or so ago read a few things and talked to a few guys and they told me something about my ecm/pcm making the torque converter drop in and out due to a bad ground, battery or altanator replaced all that still happening wondering if I should just rebuild the tranny or if there is something else I'm missing its my first diesel so I'm kinda learning as I go if anyone could help it would be much appreciated