97 ZJ noise/vibration, wheel hub assembly questions
 

I'm having continued trouble with some noise/vibration on my 150k ZJ.

Maybe I'll start with the most important questions first: I replaced
one of the front wheel hub assemblies, which didn't really make a
difference. However, this being a 2WD and the axle nut being one quite
loose (no problem to get it off at all), when installing the new
assembly I didn't take the 175 ft-pd torque seriously and only snugged
it up good, but didn't really care about the torque, and I'm sure it's
a lot less than that. I didn't realize that torque may be needed to
preload the bearing, I think I even read you can drive (the 4WD)
without a drive shaft entirely, but now I'm wondering? I'm 300 miles
from home, but if this is a critical issue I should probably torque it
up before driving back. Of course I may have screwed up that new
bearing already...

Now for the longer story, where I mostly still have no clue what's
going on. I'll give some background, which may well have nothing to do
with the problem at hand.

A couple of months ago, I replaced rotors and pads in front, after
getting vibration during braking (it had been that way for quite a
while and kept getting worse). I guessed that I had warped rotors, and
indeed the brake job fixed the braking issues.

A month later or so I had the state inspection done. I noticed the
mechanic rocking the front wheel quite a couple of times, which I
guessed would indicate a bearing being kinda marginally worn. However,
they never said anything about it.

Lately, I noticed some noise during driving at high speeds, kinda like
a hum or something. It's definitely related to speed, not engine RPM.
It seems to change somewhat with sideways load (steering input). My
guess was for it to come from the front left, but it's really not easy
to tell (any tips?). I had my front tires rebalanced which if anything
made it worse. I got new tires in the back, as the old ones were at
the end of their life anyway. No difference. I replaced the wheel
bearing assembly in the front left (see above), with no noticeable
change, but there's that unresolved torque issue. As far as my
understanding goes, if the sounds does indeed originate in the front,
on a 2WD it should be either tires/wheels or the hub/bearing, right?
Which leaves only the other hub assembly, unless I recreated the
problem by not torquing to spec. Another note, I tried to rock the
tires myself (car being jacked up, of course), and I didn't notice any
play at all, but neither do I have any experience. I definitely have
some hum/vibration at certain speeds now, around 45 and 65. There's no
vibration in the steering wheel, though.

Any clues would be greatly appreciated.