Strange humming noise

["George W. Selby, III" <IsuzuG@prodigy.net>]

Just two days ago, my 4kcsq started making a strange humming sound from the 
front end.  It is definitely road speed sensitive, not engine speed 
sensitive, and is the same with the clutch in or out, in any gear.

It is noticable when driving in a straight line, goes away entirely on a 
right turn, and gets twice as loud on a left turn.  It is not constant, 
seems to oscillate at centain speeds, like 25, 40, 55, 70, but never goes 
away entirely.  It vibrates the car slightly, so slightly you can't even 
really feel it, you can just tell it's there. You can only hear it when the 
windows are up, when they are down you can't hear it at all, but you can 
kinda tell its there.  It is really subtle, but quite annoying.

I jacked up the car, and no CV boots were torn, and I tested the wheel 
bearings by grabbing the top and bottom of the tire and shaking, and there 
was zero play.  Could the right wheel bearings still be bad even though 
they passed the test I normally perform to diagnose wheel bearings?  And 
how does one change the front wheel bearings in case I get a wild hair up 
my ass and just decide to fix them?

George Selby
78 F-150 400M, 4 on floor, 4x4
86 Audi 4000CS Quattro
IsuzuG@prodigy.net