I agree with general, looks like a cage for the thrust bearing.. on the passenger side of the transfer, there is a port with a hose that runs up to the scavenger pump On the passenger side of the trans housing. If you remove that line and the fitting that connects the line to the transfer case, you should find a mesh screen filter That keps debris out of the scavenger pump. I suspect you will find more parts in that strainer… This is a possible issue and they directed that bearing be changed at any point the trans was going to be worked on. its all the way up under the case behind the P6 clutchpack all the way at the back end of the trans/transfer.
you cannot remove the transfer, or even that P6 clutch cover with the transmission installed, without cutting crossmembers out of the way… there are 2 shafts(one inside the other, output and P6 clutch that gives us first gear) that extend all the way back to the rear of that clutch housing, so the transfer has to move quite a ways to the rear to clear those shafts…
here is that filter on the 24p parts diagram… The thrust-bearing that fails is located where the arrow is…
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