When I was swapping the ZF5 into my current 85 F250, I also couldn't get the transfer case to separate from the transmission (during disassembly). I can usually just wiggle up and down on the transfer case and it will slide back. Not this one. I got my dead blow and smacked on the transfer case really hard (not recommended-see above). When it broke loose, I barely got my face out of the way before the deluge of 80/90 could hit it. It did get my right shoulder. The transfer case appeared to have been glued to the transmission with at least a full tube of RTV. The 80/90 came from the missing rear transmission seal (not bad, just plain not there). I suppose the idiot who screwed up the rest of the truck also did this to stop a leak. The moral of the story is to watch out when you remove the transfer case. You never know what might happen.