Thanks for all your replies. I posted the same question on some other forums and I have gone through about a hundred results. About forty percent of the answers said that the problem was either not corrected or was corrected for a short time and returned. Of the other 60 percent I can't say they were all good because many were low miles since the repair and many did not drive in cold weather. So my half ass analysis is that if you get the TSB done you have a 50/50 chance of solving the problem. Since I can solve the problem by adapting my driving for the first 10 minutes in the winter I will wait. The following quotes are from someone else but they sum it up nicely.
“I took mine in due to the 3rd gear Synchro going bad on me. Dealer tried to fix it, but broke the transmission in the process. It took 3 weeks to get a new transmission. This new transmission has held up good, but finally the input shaft split in half on me. “
”Tranny never got the rebuild with the proper parts, but those who have gone, for some reason go back. Tranny is stronge, and id just shift like a granny when the tranny is cold. Not worth the effort to take it in, IMHO. “
”The Mach1Registry has countless of members who had the TSB on the TR3650. Some have been lucky & some...well, it never fixed the grind when the transmission is too cold.”
“Had the TSB done on the Mach Xmission. Was better for a while but eventually went right back to the same BS. Took it back and they put a new "upgraded" 3650 in and it's starting to do the same thing. Think I'll pull the Lemon Law thing on Ford and make them give me a GT500 since they don't make the Mach anymore.
”3650s just plain suck. Had one in the Bullitt and now one in the Mach and they were both a POS from square one. If you want a decent tranny, put a TKO in it. (BTW, Not a T56 lover here either.)”