Ok guys im new to this forum and i need some answers so i figured what a better place to ask for help on my F-150 than this place. so i have a 94 F-150 4x4 with the 5.8W AT. So my transmission went out on me on august 28th no reverse and every other gear was slipping so i put in a used transmission that had been inspected and everything checked out good. I went through all the gears and it shifted better than ever and was quiet an just great. So i went for a drive to go duck hunting about 120 miles and i get to my spot and all of a sudden i don't have reverse i could feel it lock in gear and it would roll forward about 6-8 inches then lock up like it was in gear but it wasn't getting any power to the tires. so i called a buddy and he came to pull me out of his driveway and the rear tires were locked up with the gear selector in neutral. so i just go to sleep and wake up early the next morning to try and diagnose the problem i jump in and put it in reverse and to my amazement it goes in reverse!! so i hop in and start driving home and all of a sudden my check engine light comes on and i feel and hear i vibration so i slow down and start to pull off the road when all of a sudden i hear a clunk and my rear end completely locks up and skids to a stop. so i get towed to a shop and pull the drive shaft off and the rear end is good. I then lock in the hubs to see if it will drive with the front tires in reverse and it wouldn't and when the hubs were locked and the transmission in neutral the front tires would not roll backwards!! so i locate a transfer case and switch it out and still no reverse so now im clueless unless i got duped and received a bad tranny. Anyone else have any similar problems any info would be great help. Thanks Nash