Ford Repair: 1990 f150 possible transfercase issue, 4wheel drive, metal shavings

Question
hello, i'm working on a 90 f150 5.0 AOD. i believe that one of the chains in the transfer case may have snapped or my tcase has siezed up. on the way home it was making a god awful grinding/rattling noise when i would slow down. i stopped to do a visual inspection(didn't see anything)> i checked the ujoints and all fluids(transfercase, trans,and rear end). when i put the truck back in gear it didnt move for a second then made a lound pop with some grinding noise and started to move. i tryed to limp it home, but on the way i felt a pop and it quit pulling. also will not hold in park. noise sounded like it was coming from the tcase/trans area. i'm a pretty competent mechanic but not very familiar with fords or 4wheel drive. ive looked for a used tcase and have found several elctronic shifted ones, i thought that mine had linkage(its lever shifted).are there 2 different styles of transfer case for this truck?

Answer
Hello and thanks for the question...I'll try to help.
I think you have transmission problems before the transfer case. The parking problem is an indication that the parking pawl is not locking in.......that is in the transmission.
My suggestion is to drop the transmission pan and see what's in there. Also, drain the transfer case and filter the fluid coming out......see if you have metal shavings.
Erik