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

My experience has been similar

First diff took about 2k to get loud.

Second diff has been louder and wider in range than my first one from mile zero.

Knowing what I know now I should have kept my mouth shut. This new diff is horrible.

They told me the howl comes standard with the long bed... absolutely BS.

 

Wonderful.

 

That is ridiculous. Did you file a complaint with corporate?

 

Yea, my new diff is worse than my old one was. I keep telling myself the first one would have gotten this bad too... But I'll never know.

 

Yup. Need to call again with the new diff though.

I agree, ridiculous

 

That is such a line of crap! I would have laughed at them if they told me that. I'm sorry you're having this issue, but that is ridiculous.

 

Yeah me and the service advisor manager were incredulous.

He was just relaying what the Toyota engineer told him.

So it needs to escalate above him. He was cool about the first replacement so I have no problems about the shop.

At my 10k though I'm going to make a stink about it to him again. But first I need to update my current complaint with Toyota Corporation.

 

Seems pretty common that replacement diffs are going bad quicker than, and then ending up worse than the original. There are obviously people here that know more than I about diffs, but doesn't this point the finger even more so at the carrier? Theory: carrier is bad, diff gets replaced, carrier settles in and picks up with the new diff right where it left off with the old. Why else would it happen so much quicker than the original? Seriously, bad out the door? WTF?

 

Is it possible, it's because the suspension has settled a bit since the truck was new?

I find it hard to believe that the differentials for the Tacoma are made by one company and the differentials for the rest of the Toyota product line are made by a different company, or different companies. It is possible that drivetrain geometry is causing the problem.

Are the guys with lift kits on their trucks having more or fewer issues with the rear differentials?

 

Toyota either fired all the good engineers, in favor of cheap replacements, or is not putting enough time into the fix; especially this being a supplier problem. I think the problem is dynamic; it comes and goes based on load. I know the frequency of the howl is equal to the ring and pinion tooth mesh frequency. Maybe the carrier is moving a few thousandths, within its bearings (and lash adjusters) based on load applied (feathering throttle or not). Perhaps the backlash is varrying based on these dynamics.

 

The official response given to me, from engineering relayed via master tech, was that it is normal resonance frequency of the gear set and that i am most likely hearing it due to the (lack of?) sound damping material on the truck. They said they were confident it was not causing any damage, but to of course let them know "if it failed."

When I asked why I haven't heard it on any other vehicle I drive, or what I was to do about the annoying sound, I was told there wasn't really anything to do, it is just a characteristic of the vehicle. A few days later I received a call from corporate, after complaining about the new one making the same noise, and they informed me they wouldn't be pursuing the issue any further, that they believed the new differential howling was not an issue and no longer justified a warranty repair.

I slowly listened to it getting louder over another 14k miles and mentally I couldn't handle it anymore, especially on that one day every month when I listened to it for 30 miles on the ride home from work, only to log in to my computer and make my loan payment to Toyota.

 

Keep leaning into them. Threaten lemon law. Get a sweet warranty. My budd was told the same thing you were told. Then, he was offered a buyout. He rejected the buyout and received a 8 yr 125k Platinum warranty. Seems like a characteristic of his truck. Lol

 

I believe he got rid of the truck because of the Howling

 

Understood. I would be pissed. There is no way the consumers should be eating this. Maybe having a FEW lawyers around is not a bad thing.

 

I was pondering if undercoating or rhino lining the rear axle would soften the whine. Also thought if it would cause the diff to run hotter due to the coating.

 

So I wonder what the guys with Dynamat are saying? Most rear differentials will make some form of noise (I can hear a whine from my 2016 Yukon) but I've owned a lot of vehicles in my life and I have never had anything this close. Also, my second gen Tacoma had zero rear diff noise coming into the cabin and it was a heck of a lot louder than my third gen so I call BS on this. Toyota touted how quiet the third gen was only to now say it doesn't have enough sound deadening? Geez, here we go again.

 

They gave me a 5 year 100k mile platinum warranty for the issue. My stance on that was that it was really nice of them to do that, but it didn't really help when my major problem was being deemed normal and not a warranty issue anymore. It did make my feel a little more confident in Toyota though.

Unfortunately with the howl, the buzzing vibration through the steering wheel at 2100-2300 RPM, the really odd engine management/torque delivery, the dash rattling, the head unit repeatedly restarting at random times when I turned the truck on, the hood separation issue that just showed up, poor wind seals, etc etc. I just couldn't justify the cost of the truck and having to put even more money into it with normal maintenance items down the line. Mentally it was too much for me to keep sitting at the dealer for a brand new, $32k truck. I could have dealt with most of the other items, but the buzzing vibration and the howling were too major for me, with no clear fixes anywhere in sight.

@shakerhood is correct, I sold the truck to a local dealer and got 31k for it with 22,000 miles on it. It now sits on their lot for $36k. More than the MSRP was for it when it was new, and quite a bit more than I payed for it brand new. I just hope the people that go and check it out read this forum and look for those issues before they drop that kind of money on that truck. If they are OK with it, that is great, I couldn't handle it knowing what I had received for the price I paid.

 

Wow! You gave $32k new, drove it 22,000 miles, and got $31k back for it?

 

Yes, I bought it out of state and then sold it locally here in SoCal where the prices for 4wd Tacomas are even more inflated. I'm sure it will sell for more than I bought it new.

 

Canadian here.
So I finally took the Tacoma in to the dealership, Kentville Toyota, for the front end howling noise (Holes in lower control arms) and rear end howling noise (improperly assembled rear diff) and they found two tsb's that are suppose to resolve the issues.
For the front end it's the plugs as we all know.
For the rear end it's the heat shield on the tranny. I'm certain this is not the issue but I'm willing to work with thier arrangement. If it still makes noise I'll take it back and we'll see what they say next.
All in all I'm happy with my experience.