727 with fmvb question

How big is your cooler? Unless it's a pretty good size cooler it may not be enough by itself. You have to remember you need air movement across it for it to cool and in traffic you probably didn't have much air movement. Stop and go traffic with just an aux. cooler can overheat a trans. pretty fast. Being over full (even if it's not a lot) can also cause fluid aeration.

And as TB said please explain "Lost 2-3 and 3-2"? Are you saying 1st and 2nd worked fine, just no 3rd gear?