A while back, a friend and I attempted to replace my radiator. There are two metal lines going into the bottom (maybe middle) right side of the radiator as you're looking towards the rear of the vehicle. I figured those needed to be removed to get the radiator out, but found when I attempted to remove those lines, I heard a loud hiss, as if they were pressurized. So I quickly tightened the bolt that was holding that secure. Long story short, ended up taking it to a mechanic to have replaced. Fast forward a few months, and when my transmission heats up past 167 or so, I get a hard shift going into 3rd gear.
I changed the fluid and filter, and filled to the correct level while transmission hot and engine running. I used Dex 6 as I have found that is okay for this transmission. After searching the forum I have seen a few posts about transmission coolers coming from the radiator. I'm wondering if I altered the pressure when I messed with the metal line going from the radiator to the transmission (google search told me that's where it was going to).
I'm at a loss for what to try now...Any help is greatly appreciated.