Diff and transfer case oil change - new plugs and gaskets?

[Kraggle Lurker Find all posts View Profile Close Kraggle]

Any time I change the engine oil, I'll fit a new plug with new gasket.

This'll be the first time i've changed the front and rear diff, and transfer case oils though. Should I be replacing the gasket/plug on the drain plugs for the diffs and transfer cases, as well as the filler holes too?