Thanks to all who've offered advice on my bass-fiddle noise.

No consensus, certainly. Majority opinion has it that it is wheel bearings
(just not the bearing I changed). A substantial minority think that it is a
large flat surface vibrating and making an acoustic chamber of the inside
of the bus. Then there are your splinter groups, heretics, eccentrics and
radicals, each with an opinion. ;)

It seems to me that it is probably not caused by air movement. I am not
firm on this because it sure does *sound* that way, that is the character
of the noise, but there is the fact that the noise is completely silent in
curves, even fairly gentle ones. A curve shouldn't cause a shift in air
movement substantial enough to cause the noise to cease immediately, seems
to me--and if there is a side wind I should sometimes have the noise be
louder in a curve than on a straight. But that never happens. This all goes
for movement of the fiberglas top, too. I should notice some correlation
between wind direction and wind speed, and the presence of the noise; but I
don't.

So I'm betting that the genesis of it is mechanical and it's being
amplified by the body of the bus. This weekend I'll get new seals and
repack the other three wheel bearings, then see if the noise changes or
goes away. One person said that he'd had this exact same thing happen and
solved it by rotating tires front-to-back, so I'll do that while I have the
wheels off. If the noise stops then, I'll never know what caused it (unless
I find some blue bearings), but WTF. I just want it fixed. If none of that
works, I'll...decide what to try next. ;)

The bearings I pulled out last week, I threw away. They looked fine, but I
was pretty sure they were the problem and I was too busy patting my
conceited self on the back for knowing where to look for the problem to do
any actual *thinking*. <smolder> Forty dollars' worth of perfectly good
spare bearings right in the trash.

--Ken
  '71 Bus, '68 Westy