What year is it? Didn't Ford and GM work together on a tranny recently? I think it's that 6 speed auto.
the 6 speed auto is an Allison GM and Ford use them because they can't make a reliable automatic truck transmission to save their asses. Chrysler shoul too...
I don't know, all I can say is that I have had many GM products that have Crapped out (NEW CARS)..I had to file Lemon Laws on 2 of them and won. We have had since the last lemon law, 97' we bought FORDS and we NEVER had any problems. My Excursion was even used and we NEVER had any engine problems with them, but I can list ALL of the problems that our GM products had.
In case you were wondering, I am still Keeping my GMC, I still love it...