3rd Gen Poll: Rear End Noise howling when feathering throttle

The toyo customer care "specialist" contacted me this morning to follow up on my complaints / issue. She said she was going to contact dealer and ask about them "taking me for a ride" in another 2020 OR to demonstrate that this is indeed a "normal" occurrence as the dealer informed me. I'm sure the dealer/toyo will absolutely find one on their lot that does exhibit this noise so they can can "see, they all do it". If they pull that, I'm going to point randomly to a different one and ask to ride in that one.

 

The problem is that the howl usually develops after the diff breaks in (few hundred to a few thousand miles). I would refer the customer service person to this thread and be sure to make a point that the noise takes time to develop.

I'm still thinking the gear mesh vibrations are creating a tuning fork effect with the axle tubes, springs, and/or frame...

 

Are you asking about spider to side gear backlash? Won't do a thing as they aren't rotating relative to each other when the whine is occurring.

I was just explaining that yes, Toyota does set up gears to spec and they even set up to more specs than a typical gear shop checks.

 

Shimstack, How do I approach Toyota to get them to check into this and open it up for actual examiniation? I'd prefer they not
1) tell me again, "this is a normal whine, get used to it" , "even the new Tundras are doing this"
2) simply replace the rear axle with a unit that possibly exhibits the same quality whine and or a rebuilt unit that still has this wonderful sound effect as others have posted about.

I'd actually prefer they rebuild / repair or replace the parts that are creating the whining sounds and get it set up correctly (assuming it's not quite right). Some here on this forum are stating that this whine is normal and doesn't create a detriment. Ok, probably correct on the "no failure" possibility. But if it was "normal", 100% of the tacomas would exhibit this "effect". However, I've not ridden in a tacoma that exhibited this whining phenomenon, 2nd or 3rd gen.
I owned a second gen 2wd for 120k miles, my son has a second gen 4x4 (117k miles) , Nephew has 3rd gen TRD 4x4, neighbor has 3rd gen limited 2wd, A close friend has 2019 sr5 4x4, and I've ridden in others, both 4x4, 4x4OR and 2wd that don't have this annoying quality. So I guess I'm just extremely lucky to get such a fine example.
My dealer tells me things that aren't true. Such as "yes, we checked all the fluids and they are fine" . I posted what I found when I checked.
Hopefully, if Toyo decides to help with this, I can go to a different dealership. Ive grown to distrust my closest one.

 

You should contact East Coast Gear Supply and ask them if they think you should bother getting It looked at. They are a pretty honest business and didn’t try to sell me on anything when I asked. They were extremely familiar with the noise issue on the 3rd gen Tacoma’s. They specifically said it wasn’t a setup issue, and that changing gears won’t help.

There’s even a tech note on their page for the 8.75” rear end

https://eastcoastgearsupply.com/i-23993416-8-75-tacoma-elocker-third.html

 

Ha! Thought this was wind noise, I have the same thing on my 2020 TRD Pro, 3000 miles on it. Now I know where it's from. Has done it since day one.

Also noticing a loud whine noise from the back, sounds like a fuel pump in overdrive, but only when the truck is moving above 20mph, so it's not the fuel pump.
The whine gets louder as the truck gets warmer from driving, so loud people on the sidewalk look towards the truck like "WTF is that noise?" As if I'm driving a beat up 1991 F150.

Some serious lack of quality control 'Yota has these days.... rattles, hums, vibrations.
My FJ was rock solid, quiet and smooth.

Wish they'd go back to making all their vehicles in Japan.

 

Can't complain my 2020 was made in teaxa's, its every bit as quiet as the indiana built tundra i owned. Really the only thing i can pick on is the seat belt buckle rattles against the door pillar if not buckled.

 

Again, looking at this as a differential problem will not produce results because there's nothing wrong with an axle strictly because it whines. Gears whine, these axles whine, it's just part of the physics. Where the issue lies is in the nvh. There was not appropriate attention paid to attenuating the frequencies associated with the gear noise around 60 mph. That's why suspension changes and stuff can randomly fix it as it changes the frequency ratio of the system. The classic fix for something like this is some adjustment to the properties of the system being excited (suspension, frame, body) and not the source (gears, axle).

If the driveline/gears generated a felt vibration then you would go to the source, but since it's acoustic you can just go to what's being excited.

An nvh study would be a bit of trouble but would probably identify a few fixes.

 

"h" must be harmonics, but the nv has me lost.
Is there anyway, has anyone tried to isolate the rear drive train from truck? The Axle only has two points of contacts that I can think of (without looking again). maybe adding an extremely dense rubber (industrial flange gasket?) material in the leaf spring stack? Sorry, Just thinking of "what if's". may have been attempted.

 

Noise, vibration, and harshness. It's basically its own branch of automotive engineering.

 

Well back to 75-90 Amsoil severe gear. Took for a spin and seemed noisier, but I think its just f***ing with my nerves now. Considering buying the TSB body mounts but they are expensive and probably wont make any difference. Almost lost my shit and traded in for a GMC Canyon today! Was so quiet at all speeds. The amount of time I have spent fucking with this fucking noise is starting to pile up. Several types of oil, noico on back cab wall and fluid film on the leaf springs has also started to financially pile up. All this fucking time and money for no change. Its a NVH Toyota fuckup they need to fix and stop with the “its norma” BULLSHIT!!!! Maybe they should send a truck to Ford Dodge or GM and fix the problem they cant seem to.

Please god let someone figure out this noise issue! ​

 

I feel for ya, man. I was in the same boat. After doing the back and forth with corporate on about 30 phone calls over 40 hours I finally traded off the truck. Couldn’t take it anymore. Lost money but regained my sanity. Got a 4runner instead. Because Toyota’s are mostly good trucks.

 

All toyota needs to do is look at the tacomas that don't howl, and compare specs to the ones that do. They should find the difference in the ones howling? Imo it shouldn't take a rocket scientist to figure it out....or maybe they already know.

 

Well, toyota just called me back (again).
Rep said to go to dealership to test drive another "like" vehicle to demonstrate "whine" is normal. This really doesnt satisfy the fact that it isnt normal (I corrected her) , only that it is a reoccuring issue and needs to be addressed. I further told her that normalcy entails 100%, all like models will have this whine. Which obviously they dont. She became slightly belligerent and started telling me she is not a tech. And for me to not interrupt her.
Disappointed is an understatement.
I did call east coast gear. Talked with a nice young man for 20 minutes. He suggested trying a conventional heavier gear oil. Non synthetic. No guarantees.
now have concluded that for distant trips i need more comfy headphones or ear plugs.
I wont blast the truck. I do like it. This issue just makes one upset. Its been ongoing for years now and toyota seems to not care. And they sure dont tell you about it before the purchase. Would be nice to have had a disclosure.

 

I just tried 85/140 non synthetic. Didn’t really make much difference. I have also tried new differential, foam between the bed and cab, multiple oil weights, Stuck noise dampener on back of cab and fluid film on leaf springs. Still screaming between 50 and 60. It drives me batshit crazy.

 

Starting to wonder if this howling is a wind issue though or over some part of the truck. I just returned from a fishing trip, but was talking with another 2018 sr dd cab tacoma owner with an auto v6 that claimed they can get their truck to make a singing sound if the hold the speed to precisely 55 mph. Anything above or below it goes away. They said they just avoid that speed and all is great.
On another note at 2500 miles now, i think the seat in my cab is getting broken or the truck suspension is beginning to ride smoother. Engine/transmission now even towing is working better then i could ever hope for. Getting to really like this truck more and more.

 

I wonder if you spoke with the same bitch i did... i should have saved that righteous anger for the engineer

 

Did someone on the thread say they installed blocks and still had the howling? Im now looking into a 2/1 bilstein 5100 lift with 265/75/16 tires?

 

Got a question...are the ones even with a tonneau cover howling to?

 

I have a 2.5” block, no difference, still howls. Someone reported an icon AAL fixing it, maybe try that

Sure are. Tonneau makes no difference