Does anyone recognize this noise? (video)

I'm hoping for help narrowing this one down. Maybe someone else has run into this before.

Wait for when the camera is in the middle of the cab.

http://youtu.be/U3ZeRxcevi4

Temperature-related change: it gets quieter when ambient temp is cold. Nonexistent below freezing. It didn't do it when I bought the truck (winter) and it's most apparent when the temp is 80+.

Speed: I can hear it from 40-on up if I turn the cabin fan off, but it's most evident between 55-60 mph. Strangely enough the pitch never changes; it's always that warbled sound and it doesn't get higher or lower.

Steering: the cycle speed of the sound gets faster when turning right, slower when turning left, but the noise doesn't change volume either way. Doesn't sound like any bad wheel bearing I've ever heard. There's no growl and the pitch is constant.

It will completely disappear if I go over a small bridge that picks the truck up a little bit.

U-joints feel tight and are greased, no vibes at all, wheel bearings silent if truck picked up and they're spun. Front wheel bearings replaced by dealer before I bought the truck, and I'm wondering if it could be the tires because they have some odd wear on the inside shoulder thanks to the old bearings' sloppiness.

I can't feel play in the rear bearings and the seals aren't leaking any diff fluid. Maybe it's just early on in its problem? But the sound seems to come from somewhere forward, not aft.

I first heard it about 3k miles ago and it hasn't changed significantly, although I think it might be louder when I take the tires above 40 psi. They're at 38 cold during video. Lug nuts are freshly checked at 80 ft-lb.

Could driveline angle do something whacky like this? The center bearing rubber has a fair amount of sag in it and the factory leaf springs aren't as perky as a fresh set. Although, the turning thing doesn't match.

Like I said before, has anyone heard this noise?

 

Forgot a couple things....

No change if I put it in 4WD.

No change if tranny put in neutral, no change if I'm in 4th gear or 3rd gear.

The noise is not load-dependent. It happens if I'm accelerating, cruising, coasting, decelerating in gear, whatever.

 

i dunno, check for wind related, loose mudflaps, motor protector rubber things etc. i dunno

 

Jeezus, I wish my truck was that quiet.. srry man I got nothing

 

I didn't see anything loose other than the front skid missing a bolt I broke and haven't gotten around to fixing yet other than the ziptie band-aid.

Well if anyone has any more ideas it would be appreciated.

Otherwise I suppose I'll continue my current plan... change out tires, if it still makes the noise then put up with it until it's bad enough to pinpoint. As it is the radio doesn't have to be very loud to drown it out.

 

my truck was doing a weird kind of buffeting noise between 50 and 60mph. I don't notice it anymore. think it was wind related

 

Maybe the center support bearing on the rear shaft is whining at you. Really hard to diagnose it just by looking at it, or even shaking it, because the bushing that surrounds it gives. If you can attach your camera underneath your truck somehow, record, and replicate the noise, you may be able to narrow down where your problem is.

 

I was thinking it was carrier bearing related as well. It sounds driveshaft related to me

 

I think you guys are right. I crawled under the truck after I got home and the driveshaft on both sides of the carrier bearing was too hot to touch.

Looks like I'm about to have an expensive weekend.

 

Wow, check the u joint there too. Advance auto has the bearing for about $60, and moog u joints run about $20. If you order online and pick up in store, you can throw 15% off at least.

 

Yeah, it's got sag, probably from the heat. Hopefully the driveline shop up in GR can hook me up.

 

I tried the advance auto site but it wouldn't give me bupkis for exact fit. Maybe I screwed up somewhere.

Yeah, that u-joint is probably cooked. It's not loose but it's going to have to come out anyways.

I know what the dealer would say.... $400+.... I could go one piece for that.

 

This is the one you need http://shop.advanceautoparts.com/we...hicleIdSearch=-1&searchTerm=934401&showTitle= it says $67, but throw a discount code in, and you got a win. And don't worry bout their fit check, it's not always right. Cross reference other sites if you don't feel comfortable.

 

You might also want to check out the "wookie strength carrier bearing mod" lol

 

Update for the archives... I rotated the tires in an "X" pattern today just for the heck of it. The noise is completely gone! I drove a good 30 miles at its most excitable speed - nothing. Just sweet sweet bliss, and the bit of 5th gear whine the R155 tranny is good for. Relief at last!

Now I have yet another excuse for getting those LTX MS/2 tires this year.