I'll post in here, since I've had similar problems...
New to me 96 4x4 auto, everything stock..188K miles
Once, after a long highway drive, I got off the freeway, and then the tranny wouldn't shift correctly. Seemed to be stuck in a high gear. Also would shift erractically and the tourque converter didn't seem to be locking. OD light was flashing, but no CEL. This has happened once in the past month, but I don't drive it that much. Turned it off, let it sit for 15 or so minutes, and now everything is smooth. I have not had any codes checked, and I guess there are some since I had the OD light flashing. Correct?
However, I have no idea if the transmission has ever been worked on, and of course that is a worry, since E40D are ticking time bombs.
That brings me to my actual questions...when the torque converter fails to do its job, what causes this, most likely? The torque converter is a mechanical piece, and is controlled electronically by an external solenoid, I beleive. Now does the actual torque converter fail mechanically, or is there usually some electrical component that fails? Also, when people get the tranny 'rebuilt' what does that usually mean? Does that mean every component gets replaced with a master rebuild kit, or are there just certain parts that are replaced because they usually fail? How many electrical components control the operation of the trans? Are these all external, or are there some components that are inside the trans that require a removal?
Now if I do encounter further trans issues, I will take it to a shop, but want to be as knowledgable about the subject that I can, so the shop won't just throw parts at it or recommend a full rebuild when not necessary.
Lastly, if I do ever have to get it worked on, I'll need to know what some stronger, more reliable parts are to use in the fix, so some recommendations will be appreciated.