trans flush gone wrong I F*d up

[e200e]

96 4.0 123350 miles she was running great then I decided to do a transmission exchange because the fluid wasn't low and was clean and I like to take care of my truck. I replaced the filter and pan gasket and put new mercon v in it and now it doesn't shift. I throw it in gear and it doesn't do anything it just behaves as if its in park. Sometimes it will start to move like its trying but... At first it flashed o/d when shifting, then i disconnected neg cable and returned later let it run in idle a bit like 10 min. When attempting to shift o/d wouldn't flash anymore but same thing. I disconnected neg cable again and just let it sit over night. This morning same thing and no o/d light. I'm assuming my truck needed the old transmission fluid. I highly regret doing the transmission flush I assumed I was okay but I was wrong. What could I do now? I was thinking reflush and putting 1-2 qt of the old fluid that I still have because the rest I took a transmission bath on my head and all over my shirt and lucas transmission no slip additive + the new transmission fluid. As a noob automotive technician I always find myself learning the hard way. I guess this is just another class in the school of hard knocks. Any input I would appreciate I do need the truck as a daily driver.

 

[e200e]

Wait, two o rings came with the trans filter do I need them I couldn't find a spot for them could that be my problem I checked the old one and didn't see any o rings so I assumed the were unnesscary.

 

[e200e]

^^ never-mind i'm freaking retarded I see where they go. Lemme try with the o rings and I'll let yall know how it goes.

 

[SoNic67]

The filter needs to be sealed perfectly inside the input bore. If that bore has a scratch (it's aluminum), pump will "suck" air instead of oil.

 

[e200e]

Yep I put the o rings on and now it works and shifts great. I can't believe that was the problem. The outcome was much better than I expected another lesson learned don't forget your o-rings kids. This thread is adjorned thank you very much explorerforum.