2003, 3.8, AWD, T&C, No High Gear

[Upstate]

My '03 with 100,200 miles stopped using (seemed locked out of) high gear while towing a 2600 pound camper. I got it home and to my favorite tranny shop. He read the code, said it probably was a high temp incident. Added a cooler, serviced the unit and said I had to go to a dealer to get reflashed. I did that. A few weeks later, the next camping trip, it did it again. So far only did it while towing. By now I had learned not to panic, just park, stop engine, wait a minute and it resets. I was having other work done and asked my favorite mechanic to take a crack at it. He said the code indicated a bad solenoid and he replaced the $567 dollar part. A couple days later it did it to my wife (finally) while not towing. Brought it back to mechanic. He said it would not do it for him. That was two weeks ago and it has not happened since. Maybe, with all the other work, he forgot something and picked it up without telling me? In a couple weeks I have to tow the camper 150 miles to its winter garage. Should I try it? The pans been dropped twice now with no metal bits found. Thanks for any advice!

[Upstate]

It towed! It started locking out high gear without towing. I bought some Chrysler manuals and a mechanical failure was a real possibility. The filter was holding the fragments internally and no one looked. Problem was a "clutch involved with the torque converter". Rebuilt for $2800 with tax. Turns out no electrical issues, no bad grounds, just old fashioned over use. They said even though I could manage 50 mph at 4000 RPM it was limp mode. I still need to tow with it so I hope I get another 100K. Figured I'd fill people in, enough people looked.