Need Help Trany shutters
Have 02 F250 with the SC installed for 4 years. If i run it hard it shuttered in 3rd gear just after it engaged and and locked the converter. It used to shutter in 1st and 2nd and 3rd befor i had a shift kit installed, Now it only does it in 3rd at 50-55 mph. Two Days ago i reprogramed to the stock chip and now it doesent"t do it that mutch. I recently pulled a trailer that 6600lb and now it does it on a incline and accelerating at the same speed 50-55 I noticed the once the rpm went up 50 rpm and shuttered i let off, I suspect it to be slipping when it is shuttering. I am thinking of going on a 1200 mile journy with the trailer.
Is this normal or is the trany on the way out?