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

I broke in my stock rear gears just like you would if you went aftermarket. Changed front, rear and transfer case oil @ 500miles. Absolutely no noise 7000 miles later.
BTW it did look dirty with little metal flake look to it. Just cheap easy insurance? Or overkill?

 

That's my guy I run amsoil also good stuff

 

Oh yeah. I’ve been running severe gear amsoil since 500 miles. Front and rear diff.

 

One of my service's transfer case 28k mi still looked nice. Had a gold color slightly but wasn't bad at all . Serviced my rear end one time at 50k miles , yeah not again too long

 

fwiw.

'22 TRD Sport AC 4WD MT ~ 15K miles with chin strap on. i have a slight howling noise from what sounds like the rear diff around 50-60 MPH as i feather the gas pedal. seems to be more noticeable when i am going down a grade as opposed to on a flat. the noise has been there from new and the truck 'broken in' gently.

i recently changed the factory fluid to amsoil

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 severe gear and there is no change in the noise level. the original fluid was not terrible in appearance and there was only the normal metal flaking on the magnetic drain plug.

unless the noise worsens, i have no plans to take it to the dealer as it sounds like this is normal tacoma stuff from what i read here and elsewhere.

 

I recently switched to Amsoil

$30 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 for my Nitro 4.88s which do howl some, and it definitely reduced. I’m now wondering if I should have gone to 75w-110…

 

if you try the 110 let us know if it quiets it down at all

 

Will do, but I doubt I’m going to spend another $80 to redo it if I’m being honest. I’ll put up with a minor hum for the supposed better MPGs.

 

Just had my differential replaced under warranty. No whine on my way home except from the toddler in the back seat. Asked the tech if I should follow the 500 mile break in procedure like you would with after market gears. Long story short, he’d never heard of it and doesn’t recommend changing the oil for 50k miles… I’ll be following the 500 mile break in procedure and changing the oil to Amsoil severe….

 

Well I am back and must be a gluten for punishment. Picked up a '23 offroad again in March and back in the howling game...... My local dealer said they couldn't hear it today so I have to go to one I know will fix it. But once replaced I will def go the Amsoil route after 500 mile break in like others are stating.

Its odd.. I have had (2) 5th gen 4runners with no howl, this is my second 3rd gen Tacoma with a howl and my '21 Tundra howled as well. Seems to be the US/Mexico built trucks and I am wondering if they are sourced differently than the 3rds for the 4runners (compared to the Tacomas).

But not swapping fluid until warranty replaces it.....

 

That isn’t going to fix it by replacing diff. They replaced my diff on my 2023 made zero difference

 

I just had mine replaced on a 23 TRD Sport, and it is no different than the original one.

 

So we're just wasting time going through a replace?

Any update on your whine?

 

- 1 month old 23 2wd Sport with 5k miles and no whine
- 20 2wd Sport with over 100k miles and no whine
- 18 4wd Sport with over 240k miles and no whine
- 16 2wd Sport built during the first month of 3rd gen production and it whined when it was parked or driving. Two new complete rear ends and eight different flavors of rear end lubricants did nothing to resolve the problem.

 

It’s whining again. Not as bad as the original but it’s there. Changed and replaced the OEM oil with Amsoil severe gear oil after 500 miles. After all that I learned that it’s not so much the diff that’s whinny it’s the whole rear end design that makes it whine, diff,leaf springs, shocks etc…Resonance is what they call it. There’s some pretty good threads on it on here that explain it better than I can.

 

It's just strange why some do whine and others do not. It looks like after building the same truck for eight years, Toyota could figure out what is different between the trucks that do and the trucks that do not whine. I had a 2022 before the 2023 and it did not whine. I had a 16 that did and 18 that did not. I understand it is a resonance noise, but I still feel like it caused by the set up of the rear diff. causing a vibration to resonate through the leaf springs.

I am not sure going through a replacement is waste of time. However, I feel like the odds are against you getting one that does not whine. This is why so many dealers are reluctant to replace the diff. Most have had very little luck in stopping the noise. There best line of defense is to say it is normal. Once they make an attempt to repair, it now becomes a lemon law situation if the customer pushes the issue. I know first hand, they want to fix your truck, they just do not have way of doing so.

 

My 2021 was approaching the 3-year limit of the factory warranty. I took it in 3 weeks ago and told the dealer I wanted it checked. They did hear the whine and the service manager said mine was not near as bad as some he has heard but that he would order the "kit" from Toyota to address it. He claims they have had about an 80% success rate in removing or significantly reducing the whine.

I took it in today and according to the invoice they replaced the damper, pad and cab mount stopper. It took about 3 hours. The whine was gone and unnoticeable when I drove home. Not sure it's a permanent fix but it really seemed to help thus far.

 

What does one do, if the rear differential never whines?

 

@smitty99 was a footwear connoisseur!

 

Buy a sound generator?