Just to be clear.....putting my transfer case, with all the hole sealed up, in the parts washer would be a BAD idea. Correct?
It is currently off the truck.

 

It should have a vent on the top, without the vent it will build pressure when it heats up and leak past the seals. For deep water travel extend the vent lines up into the cab with fuel line and a vent cap(scrounge some diff vent caps)

 

woops! I totally screwed up the typing on that one! I edited it.....