So, on a shorter road trip a couple of weeks ago, I began to notice a
dull roar and a 'wuh-wuh-wuh' noise at lower speeds that varies with
the rolling speed of the van. (In and out of gear.)

In the following few days from my vantage point in the driver's seat,
I placed it at the passenger-side front wheel bearing and ordered a
replacement from Van Cafe. That weekend, I pulled that wheel, pounded
out the old bearings, packed the new ones in some nice synthetic
grease, pressed 'em in, and put it all back together. (It's somewhat
of a scary realization now knowing what holds the front wheels on...
:)

The noise didn't stop.

So I'm guessing I made a misdiagnosis and now I'm thinking it's the
rear wheel bearings.

I've put three or four hundred miles on it since I first noticed the
roar and wuh-wuh noise. The roar doesn't seem particularly worse since
then. I do notice that the roar is a bit louder (or a bit grindier?)
in tight turning in the Fred Meyer parking lot.

I have to think (and hope) it's not the CV joints -- those are
basically brand new from Go Westy, maybe 500 miles old, and should
still have plenty of axle grease in them.

Does it sound rear-bearingy? Bad set of CVs?

I'm planning to depart next week on a 2000 mile, two-week roadtrip.
Think whatever it is will go completely before I get back?

  -jrs