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

There are more cases out there (just Google them) but I completely agree that we don’t see these things grenading. Honestly, this is really a to each their own situation. I’ve stated many times on this thread that I wish the noise didn’t bother me - but it does. If I could change that I would but I can’t and it drove me insane. But, it’s not something I should have to change to enjoy a vehicle. Toyota should change it but they’ve chosen not to. If they do I’ll buy another one. If not I won’t. It’s that simple. Take care and best of luck.

 

As much as I complain about the howl, I'm happy with my truck overall. Wouldn't trade it for any other vehicle TBH

Out of curiosity does yours have the noise?

 

Sure does. But next to a 4Runner, it’s a vehicle that suits my lifestyle and volunteerism/duties well. Most have reported it howls within a certain speed band. So I simply don’t drive in that speed band. Does just fine on the highway, and doesn’t become an issue for me unless I go out of my way to try and create the noise. I plan to keep it and get 300k out of it like my last 2 Tacomas. Only issue I’ve had in 35k miles was a weeping rear main seal which is common. Fixed and still trucking just fine.

 

Most of us with the noise don’t have to “try”. It’s inherent.

Honestly this is a thread about the noise and it bothers some of us. Is the rear end going to grenade, probably not.

Does mean I have to be content with it? No.

Look up the LCA whistle or the door kazoo noise. Tons of threads on TW of unhappy people. Only difference is Toyota has a fix for it.

I have over 50k miles of a noisy rear differential and it’s just as annoying as it was when I first heard it. I enjoy the truck otherwise so I’m keeping it.

 

Our highway speeds are 45 to 55. This means the flow of traffic is almost always 58mph, the loudest speed of whine. If I still lived in Cali where the flow of traffic is nascar, I probably would have never notice it. I believe the level of irritation people have is based on the mean speed of traffic in the area they drive the most. Its a good truck and no doubt the differential is built to last, but irritating as hell. I use to like driving in silence but the whining was an icepick in my brain as two cars are always in front of me side by side at 58mph.

 

On a particular road trip I make several times a year the speed limit is 55mph for about 3 hours. I like to drive no more than about 58mph cause there’s a lot of cops around. And that’s EXACTLY where my howl was loudest.

So my choices were listen to the kazoo for 3 hours to and from my destination, drive 63mph and get ticketed, or drive 51mph and be annoyed at how slow I was driving.

This was a huge disappointment after dropping $37k on a new truck.

If Toyota gets rid of this howl, I’ll get another Tacoma. Until then, nope.

 

jk!

 

If this has been mentioned apologies (don't have the free time to read ~300 posts).
There is some variance or running change on the rear springs on 2020 ORs Some of the AT/OR SBs now runt the MT version of the rear spring.
48210-04600
48220-04240
Toyota must still be playing with trying to mitigate this issue.
No 2020 I have seen has the dampers on the C-pillar body mounts.

 

I think the leaf springs are key, based on the fact that people who have had the TSB done reported a significant improvement in the noise afterwards (the TSB doesn't even touch the rear diff). People who have changed their leaf springs out with aftermarket ones also reported good results.

I'm guessing the OEM springs (material and mass) are sensitive to the vibrations of the gears meshing in the rear diff. When these diffs are new, tolerances are tight, and vibration properties are different because of that. Hence, no noise. As the gears break in, the vibration properties change and the leafs start to act like tuning forks.

 

Someone should coil swap the rear suspension and find out for us all!

 

Hell ya!

I think we just need more data from owners who have changed out rear leafs, either with factory ones or aftermarket. Obviously need those who had the howl beforehand, and how it changed after the swap.

 

Makes it’s hard to tell too, because often when people are replacing leafs, it’s to modify and lift the suspension. In which case they’re usually complimenting that with more aggressive offroad tires, which can drown it out. Neither myself or my passengers could hear it when I had MTs. Can barely here it now with wildpeak ATs, which makes me think it’s mostly tires.

 

For a data point: TSB and new rear leaves didn’t help mine.

The best thing I did was go to 265/75r16 tires. Move the howl into the low 50s where I rarely drive.

I do have a lift I’ve been meaning to install and I’m hoping that helps. The rear will be a three leaf aal lift.

 

Had my 2019 MT in for 5k service today and mentioned the howl/whine noise around 60mph when letting off the gas. After a bit they came out and said they were on the phone with Toyota and put a scope on it to verify where the noise was coming from and that they will be replacing the rear diff. I didn't push the issue at all, didn't even mention that I thought the noise was coming from the rear end, just that I heard it.

 

Same for me - it didn’t help at all. However, mine were replaced with OEM, so I do wonder if aftermarkets would make any difference? If I were to do this again the first mod would be MTs or very aggressive ATs and then hope my hearing is bad enough where whatever is coming through won’t matter.

 

I have no lift plans but if someone can prove the leave springs make a substantial difference I might consider Upgrading them. That kind of money would be hard to swallow if you did it and it made no difference. It Hass to be something with the metal density because everyone that lives somewhere with winter like condition says the sound goes away when the weather gets cool.

 

Just my .02 cents....

I have looked at a few articles that state the 3rd gen frame is basically a 2nd gen frame with some minor changes. Hence why most aftermarket suspension parts will work on either generation. However, I cant find any specifics as to what has changed. Were the changes the cause of the whine we are hearing or are they only part of the problem? Was the original part number of the 3rd gen rear springs the same used in the 2nd gens?

I would think the Tacos and the 4runners would run the same diff e-locker to e-locker, but I could be wrong. They have a different frame and spring set-up, but I havent heard of many reports from them for whine. My 4runner has none at 12k. The SR5's run a different axle and diff, but I believe I have seen reports of whine from them as well.

So on tacos we have different axles, different rear ends, the sr5 run different tire and wheel set-ups. That would leave the frames as a common denominator.

And then we cant forget the factors of crew cabs vs access cabs and long beds vs short beds. Are there reports from each?

 

I owned a 5th gen SR5 4runner and it also had the diff whine. The whine was present at higher speeds just like the Tacoma. They both have very similar noise levels with the Tacoma being slightly louder. I feel this is normal operation due to the design of these differentials and are not at any risk of failure after reviewing the history of this post. The noise bothers some people which is understandable but this is not getting fixed anytime soon.