So my wife and I have been driving through Mexico and Central America for over a year now and are currently in El Salvador. We have a 2004 F250 5.4L gas with about 195,000 miles and a 4R100 auto. Everything is stock. We are also carrying a Four Wheel brand pop-up camper. It weighs about 1,400 pounds fully loaded.

Yesterday we had been driving for about an hour and then pulled into a grocery store parking lot. I just happened to have my window down and heard a grindy rattle from under the truck. I got underneath and listened, and it was pretty distinctly coming from the area of the torque converter. I don't know how long it had been happening. I can't hear it in traffic or at highway speed cause it's drowned out by road noise. The truck had been acting perfectly normal.

We came back an hour later, started the truck, and the noise was still there. However it was only there when I put it in gear. No noise in Park or Neutral, but there in all gears. Also, when I shifted into gear, the idle speed drops from 750 to 500 RPM. It made me nervous to drive it, but it was getting late and I didn't want to be out after dark. We drove another thirty minutes when I noticed the Check Engine light come on. And then the transmission temp gauge started crawling up. It got to just below the yellow line before there was a safe place to pull over. I turned off the truck for ten minutes, turned it back on, and the temp was normal. Drove for about another hour with no incident and, again, the truck drove just like normal. No loss of power, no hard shifting.

I checked the code and it had thrown out P1774 three times. I've now read a TON of posts about that code and have a pretty good understanding of what it means. But I can't find anyone who has had quite the same symptoms. Grinding, overheating trans, and the code. Most likely from what I've read it's the Torque Converter. Now I've got a line a trustworthy transmission guy, but I want to go in with as much info as possible.

Can I just replace the Torque Converter? If they're going to drop the tranny should I just rebuild the whole thing? Assuming they can get all the parts, how long would it usually take to do a rebuild? Am I doing more and more damage if I drive it more? The shop is about an hour away and a tow truck isn't really an option. Thanks in advance. I would appreciate any advice.