Out of curiosity, what is failing? Seems odd that they fail multiple times in certain cars, unless the driver is the cause. Not implying anything but just wondering.
The first trans failed due to synchros, which was common for the early ST's. But the dealer that replaced it never filled it with fluid...so over time it developed a whine in 4th, 5th and 6th, because of that I knew something was wrong, took it to the dealer, they couldn't figure it out (they never really tried), I eventually came to the conclusion that it may be low on fluid or maybe was never filled, checked it at a buddy's house, I was correct it was basically empty. Went to another dealer to get the fluid filled, they bottled the fluid that was in there, totaled to less than a cup...had the guy sign it to prove to the other dealer that I wasn't lying, asshole service manage at the bad dealer tried to blame it on Ford for his people being incompetent...Never got anywhere with it, after 11,000 miles the 2nd gear synchro failed again. But it was to be expected of a trans that was botched during install so...no surprise at all.