Have used search.....didn't find anything exactly like it....
About three weeks ago my 1998 Mystique w/ Duratec and ATX (almost 80k) started shifting really really really hard right after I picked it up from the dealer after getting radiator service, power steering flush, etc. It started shifting hard after I had been driving at high at about 60-70mph for about an hour.
I took it back to the dealer the next morning. They couldn't get it to shift hard and there was no code.I went ahead and had them replace the TSS because I was planning on doing that anyway.
All was well for the next few weeks until this morning when I was taking a long trip. After driving for about an hour it started shifting very hard ALL the time. I stopped for gas and when I restarted it, it was smooth again. Then after an hour or so it got rough. Shut it off again.....it was smooth and then it got rough after an hour or so. Then my CEL came on. I read the code and it was a TC P1744.
None of the threads that I found when I searched that code mentioned intermittent hard shifting. I did not have an O/D light, just a CEL. I change the fluid regularly (at least once a year) and the fluid is still fairly new. I'm afraid I'm going to have to replace the whole friggin thing.....

......any input or experiences would be greatly appreciated.......