Transmission slipping transfer case over full

Ok - this may not apply to your truck but I'll throw it out there - many years ago Ford had a problem with transmission seals failing and pumping tranny fluid into the T-case causing it to overfill and the tranny to slip because of a low fluid situation. If your tranny was low and t-case over filled and they both use the same fluid this may apply to your situation

Try the right fluid

mstamps, its funny how on all your reply there are 2 likes, mmmm funny

I am not a mechanic but I have run across when I was installing a transmission in my 2001 Tahoe I had noticed that there were a plastic box where the shift linkage goes that I never seen so I checked around and found that was if I recall don't hold me to the name but it is called a shift linkage module I had replaced it from a junked wrecked 2001 p/u and behold it work on that particular transmission also after 2 transmissions ​later I have finally fixed it not saying that is your problem just check into it before replacing the transmission or having rebuilt