M38A1 front alignment?

[Casey B]

Okay I managed to get the transfer case rear seal out and there seemed to be a this piece of what looked like a gasket that was between the seal casing and the housing that the seal fits into. Is this a gasket or a piece of the seal itself? pic shows the piece and the housing.

I tried to get a part no off it I can see 2?0WM118

If anyone knows what it should be it will help them source it out...napa lordco etc. Thanks