I've had a busy weekend (brakejob late Friday night on my Supercrew, and a trip to fix or tow my daughter's XJ about 300 miles away yesterday) But, today we rolled the Explorer out of the garage and I decided it was going to work, or I was going to kill it. It just seemed like it was holding gears against each other. In neutral, it would roll forward, but not backwards. When it shifted it felt like the brakes were grabbing, then it would take off. So I did the most illogical thing. I took it on the highway and floored it. Must have been an airblock of sorts, somewhere, because it sounded like air escaping (which made me think I killed it...). But then, it shifted smooth, no more feeling like the brakes were applied. In neutral, it rolled forwards and backwards. Reverse worked.
So, we drove it around town for about an hour and just keeps getting better. Thanks for the advice and help folks! You've been a big help... My son is happy, and can barely wait for me to release it to him. So I'm no longer afraid of automatic transmissions, but I'm not real sure I "look forward" to doing it again anytime too soon.