OK, think I've got it figured out. The noise is coming from the transfer case, seems like it tries to engage the front driveshaft when it's not supposed to. Also, I went to pull the fill plug, and a ton of extra fluid came out too, so I'm thinking I'll rebuild the whole thing.
transfer case noise
Hopefully it's not too difficult to overhaul it.
transfer case noise
Hopefully it's not too difficult to overhaul it.