I recently haven't been able to get my hubs to engage properly. If I engage the 4x4, there's a sort of rubbing sound from the right front, but no power to the front wheels. However, there's been a couple times I got lucky the right front locks followed by a whine and locking of the left. I've been able to look at the innerds of the right hub, and everything looked intact. I cleaned off the loads of grease and replaced it with WD40, which didn't do much.
my 4x4 decals make me feel like a poser

I think it may be a vacuum problem, based on what I read in other threads, but I'm not sure if the second gen auto hubs use the same PVH system as the newer ones. Any thoughts? thanks.

those arent vacuum hubs. those auto lock hubs are weak and it sounds like one of yours, or both are toast. ill tell ya that there VERY expensive to replace. alot of people, myselff included usually switch to manual hubs. its cheaper and theyre much stronger.

Just swap over to Manual Hubs.. best thing you'll ever do.. MUCH stronger, and WAY more reliable! Warn or Superwinch are you friend in brands

Would I be correct in assuming it's a fairly easy/simple swap that can be done in about an hour?

Is this what I'm looking for?

http://www.gowarn.com/detail.asp?product_id=19029&GID=

http://www.gowarn.com/detail.asp?product_id=18391&GID=

And do these include both hubs, or are they sold separately?