Jmerritt

Really hoping someone can help. Well one night I was doing the typical off roading and I went to put my 93 f150 in 4 wheel drive, well after getting back in the truck from locking in the hubs put the truck in drive and nothing happenend. I mean dead in the water absolutely nothing. I could put the automatic transmission into any gear and nothing but RPMS. When the truck is in park I can not push it but in any other gear I can push it back and forth. When the I have it in 4 wheel drive the front shaft is locked and when out of 4 wheel the shaft spins freely like its suppose to do. All the linkages seem fine I can go under truck and shift in and out of 4w by hand or by lever. The sad part nothing gave me any warning that it was going up no clunking no loud noises. Only thing that has been some kind of warning was at around 55 it sometimes would slip down a gear if I let off the gas or got it back to a certain rpm it would shuift back to the right gear. Please help is it the transmission or TC, money is tight I can change TC myself but if it's transmission I'm selling it. It does have a 6 in lift and 35s which I know makes it harder on external and internal parts lol