Weird noise in right rear end of truck. Ideas??

Ever since I bought my 2023 tacoma it has had this super weird noise coming from what sounds like the right rear end(windows up). It changes in pitch and best way I can explain it is if you were blowing over a beer bottle. It happens worse at around 38mph. At around 58mph is when the typical rear end whine starts. I’ve had the new tsb performed where they put cushions in the c pillars and the rear cab mounts dampners . Did nothing at all to fix the sound. Dealer requested a field tech to come look at it next Tuesday . You guys have any ideas ? I’m completely lost and it’s super annoying . Btw rear diff was also replaced and that made zero difference in the sound as well.

 

could it be your mirror? do you hear it with the windows rolled down? my mirror makes a whistling noise kind of. the mirror had popped out of the housing even though it still adjusted normally from inside the truck.

 

Slightly with windows down but it’s cming from the rear of the truck

 

could be air blowing between the cab and bed. mine gets a bit noisy when it's windy out.

 

I’ve thought about that too. It’s more of a harmonic noise then wind noise if that makes any sense . I wish I could record it but the other noises drown it out on camera

 

I don’t remember details, but if you search on here for Tacoma whistle
There is something that goes on with the ac co press or o believe, that causes a temporary whistle while under load . Next time it whistles turn all your fan off and if it stops right away it’s most likely that. Mine does it and I got used to it. It’s only every once in a while

 

Could be a wheel bearing in process of failing.

 

That’s what I’m leaning towards to the most so far. Strange truck only has 5800 miles

 

I heard the a/c whistle in mine too. Deff different noise

 

Did you test drive some on the lot and listen for the same sound?
I’d start there, these are noisy, not so well insulated, lil trucks.
Respectfully; I tend to think most complaints are from overthinking things.

 

Wife's Rav4 had this, we changed out the magnetic coupler, other stuff and it wasn't until we put new wheel bearings in it that it went away. Post repair I could barely hear a slight grind when I turned them and held them to my ear. Doubt you can hear it if still on the vehicle.

 

I’ve owned 4 3rd gens and this is the only one to ever make this sound

 

wow, a true 3rd gen connoisseur!
look on the bright side- you get a new vehicle every two years, so if issue is not found, you will be halfway through it's life anyways

 

That is true but I did actually plan on keeping this truck just hope they can correct the issue lol

 

Mine has a……sound coming from, what I can tell, is the back. Starts about 35 mph or so and faster. It only occurs when there is no load on the rear axle. Like when the gas pedal is feathered at speed. It goes away when I give it gas or when the engine is braking the truck. It’s not a grinding sound and not quite a whistling sound.
Is yours the same?

 

I’d say yes it’s similar to what your describing the sound changes pitch , it’s like a harmonic sound

 

Mine ended up being the rear diff. Had it replaced and no more noise. Then a couple months later they come out with this new bulletin about sound deadening and foam in the cab corner.

 

Also, I want to add that if something doesn’t seem right. Speak up and stand your ground. Make sure it’s documented by your dealership on a repair order and get a copy of that. Some dealers may think it’s unreasonable or you’re being a pain in the ass. As someone who has worked most of my adult life at dealers, now with Toyota for nine years; the good dealers want to help you. It does us no good to have an upset customer and a problem we can’t solve. So just find a good advisor or service manager and they will work with you. Toyota is, by far, the best brand I have worked with in taking care of their customers; you just have to go through the right channels and have the right person in your corner at the dealer.