Low whistle/resonating noise... Help please [RESOLVED]

Been chasing this low whistle/resonating noise for awhile, it's now more apparent after swapping LCA.

Before LCA, the noise would appear between 40-50 MPH, heard it intermittently at 65-70 MPH. After swapping the LCA, the noise is VERY pronounced between 40-50 MPH and is consistently heard at 65-70 MPH. Doesn't go away in 4wd, going left/right, still apparent in neutral, and it doesn't change pitch with acceleration/speed.

Linked to my youtube vid of the noise, linked where the noise can be heard, at 1:02: https://youtu.be/yyvcxPoxom4?t=62

I've recorded the gopro at different locations (rear differential, back of the rear drum brake housing, transfer case shield, close as possible to the front bearings, didn't hear it at all at those locations well). Where I placed the gopro (on the cross frame, on top of the nub/jacking point for a hydraulic jack) is where I heard the loudest. The second loudest was on the brushguard.

In addition, I've taped up the holes in the LCA, Nada, taped up a bunch of other holes underneath the vehicle. Didn't work. Also taken a leafblower at it, I *think* I faintly hear the same noise, but with the loud leafblower, it could be my mind hoping I did hear something. I believe that it is wind related regardless, after taking off my factory skid plate, the resonating/whistle grew slightly louder and even more apparent.

Anyone else have the same issue and was able to resolve? Praying to Korean Jesus someone can help, because this is the last maintenance item before I can start buying overlanding gear for next year haha

My truck:
2006 DBSB V6 4.0L TRDOR with 205XXX miles on the clock

Maintenance I've done so far:
- Wheel bearing hub assembly with NSK seal bearing replaced both R/L (purchased from 05Taco4x4 on this forum) at 199726
- Drive shaft rebuild (re-balanced, U joint and carrier bearing replced with Spicer/OEM) at 200000
-UCA and front/rear shock replaced with take off parts from 3rd gen tacoma (had 8000 miles on them before they were taken off) at 203349
-LCa replaced with OEM at 205072

 

Do you have a CAI?
I have a whistling noise from what I think is the CAI tube at colder temps. In the morning these days and all winter while at lower speeds, and while stopped and idling, I will hear a whistling/humming sound similar to the sound in your vid.

 

I do not have a CAI. I'll check mine anyways because I have no other leads so far.

 

Anyone else who is chasing down this similar noise, if you have a brush guard like mine, take a chance and go have a whack at it with a dead blow hammer.

Turns out, it was my brush guard, and I know which specific part of it, it was. Used a leaf blower and pointed aimlessly at first, I noticed a low humming/whistling noise similar what I hear on the road when I was hitting the specific spot circled red (not the light bar, it's the bar that the light bar is attached to). Took a dead blow hammer, bonked at it and lo' and behold, a crisp sustained note that sounded exactly like the one in the youtube video I posted. It was acting like a guitar string, constant force by the wind and resonating throughout the front of my vehicle's frame which threw me off when I was recording for the source of sound via my gopro.

So, took off the brushguard and I no longer hear the whistling noise.

 

Have the same issue, low pitch whistle at slow acceleration it is more pronounced but only under load, anyone figure 5his out yet?

 

Hey! Sorry can't help you there bud, the particular problem was resolved, it was my brush guard that caused a low hum, it wasn't under load.