Hey, so I need some insight on a new issue that came up about a week ago.
So I took a trip to the beach, and after a short drive in the sand, I started to notice a new noise.
It's apparent at speeds above 15ish then disappears above 35 or so.
It's like a "vrum, vrum ,vrum" that speeds up and slows down with tire rotation.
Noise does not change in 4wd, center diff locked, accel, decel, neutral or with brakes applied.
From what I can tell, it seems to let up when swerving to the right, and might get worse when swerving to the left. I haven't had a great place to test this.
Hard to tell which side it's coming from. It doesn't seem too loud outside, it sounds loudest from inside the cabin.
I fear a CV boot may have been damaged and some sand may have found its way in. I did a quick check, but didn't see any obvious damage.
Any other ideas? Any way to test it?

Thanks a lot!!

I just thought of something... Could it be a wheel bearing??
And I also just realized, the front CV axels don't rotate in 2wd, right?

Sounds like a wheel bearing, remember that if the sound goes away turning right it more than likely is your left one! It's opposite usually but check both, also bumper2bumper has great prices on complete hub assemblies so you don't have to press new bearings in. You just swap out old for new and you're done!

Thanks for the lead. I was looking for this company. Way easier when the bearing doesn't have to be pressed!

Cool thanks for the reference. I had a better chance to really listen to it, and it kind of sounds like its really reverberating through the floorboards. Can't really pinpoint the area. Hopefully it's just the U joints. Now to just find some time to work on her!

it does sound like it may be a wheel bearing.

and yes, the axles do still rotate even in 2wd. as they are splined, and bolted to the wheel hubs. thus they turn, if the tire turns. there just isn't any powered be supplied to them.

Ah ok. Hopefully Ill have some time to get under the truck tomorrow. I spent a lot of time under my old Trooper so I still get confused when I try to picture things in my head

Yea, you seem to be describing wheel bearings, esp with change in freq (pitch?) with speed and no changes due to braking. My front bearings bit the dust around 70k. They didn't fail but had been making noise for a short time and getting a little worse. Didn't want to roll the dice on how long 'til BOOM. Mine didn't stop roaring after some mph, but rather, road noise masked the sound. After a little while I could hear them at higher speeds. I got the hub/bearing assembly from Blue Pit Bearings. If you have a press (or access to one) and some spare pieces of steel angle iron / C-channel (and the extra time), you don't need to replace your hub (most likely). Just get an O-ring, oil seal, and bearing.

If you use a mechanics stethoscope you can hear the noise in the bearings on inspection. Good ones will be silent. Now... don't ask me how to check that BEFORE you tear apart your front hubs. I tried and it was really awkward, and mine, evidently, were not bad enough to be obvious enough with listening to them on the truck. I had already decided it had to be my bearings (couple techs said I had an issue when I brought it in for a listen with different ears). I used the stethoscope when I had everything apart for comparison's sake. It was clear then.