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

I have many rumors, educated guesses, and theories and they are all about the pinion bearing

 

Here is the post with the videos for all you late thread joiners.

 

Oddly mine is a higher pitched sound. I'll post a video tomorrow.

 

I think most people have agreed that it's drive line vibrations caused by angles being out of spec.

Toyota hasn't fixed anyones. One lawyer on here got a dealership to fix it by adding a new leaf pack and adjusting the angles. But there isnt a TSB and Toyota corporate hasn't been willing to authorize dealerships to fix it.

Edit: side note...I'm not convinced that the howl and the rumblestrip aren't related. Having drive shaft angles out of spec could potentially cause a pinion/diff howl.

 

I'm not sure. I agree with toyota, it's not the diff that's issue. They would have figured out pretty quick that all of them are not set up right or a bearing is a defective design and it's just unlikely. This is not some high tech new design, differentials haven't really changed much in the last 60+ years, plus people with the 8" axles are having problems and it's the same one they have been using. Drive line angles could be the problem, but even that is old ideas and I don't see how they could get it so wrong, I'd understand if it was a new design or had factory 6" suspension lift but it's also basically a carry over too. So I'm thinking of weird harmonics in the drive shaft or something like that. The rumble strip is a tough one. I have a manual trans and I get it coming to a stop in neutral, not sure how that would be related since the drive line is taken out if the equation. To me that issue feels like the brake system is doing something funky, or maybe even engine vibration as it tries to reduce the speed to match vehicle speed with out the help of the drive line, which doesn't make a lot of since, especially for the auto guys. Kinda lost on that one really

 

Sounds like Toyota is giving up on the diff howling noise some are experiencing, which is odd since not all of us have it. Maybe they’ll fix it on the 4th Gen, when they change the gasket material for the diff housing assembly or something, but if the rumble/shudder is also still present from the 2nd gen who knows!
I don’t have any of those either, but have heard many theories on what’s causing it and I believe there’s no cure all for every instance based on those.

I also believe that at least for a small number the howling may go away when they change to a different set of tires when the ones they have now wear out, but for others it maybe something else.

The rumble/shudder when slowing down seems is present on the 2wd not just on the 4x4. A friend who has a 2wd SR5 asked me to drive his after his CPS failed and was replaced to see what I thought about it.
After driving it, I could feel a faint rumble such as described by some here, but not every time or with any sort of consistency, but he only has 6k miles on it, and is not bothering him for now.
I’m thinking it could be a bad rear engine/transmission mount or loose or defective rear spring bushings.
Bur If they become noisy and the rumble increases we will have a better clue, but for now it’s under warranty so it’s hands off.
Anyway, these are the areas I’ll be looking into if issues should arrive, and all I can say is that this is all a royal PIA!

Best of luck to all
Cheers!

 

Driveline is not taken out of the equation when putting in neutral. Transfer case, driveshaft, rear ring and pinion all the way to the axles are still spinning.

Got a call from the dealership that they cannot proceed any further with me diff howl or rumble strip vibration. The tech contacted Toyota on how to proceed and were instructed to remove the rear driveshaft which eliminated the howl and vibration coming to a stop. Also instructed to test another vehicle on the lot which did not vibrate or howl. They waited for a regional tech to come by, drive the truck, and deemed normal operation.

I have already measured the pinion angle v/respect to TC output (off by almost 3 degrees), so on to ordering shims and adjusting CB. Ya know... typical stuff you must do to a brand new truck

 

Right, it's not 100% taken out, just figured free spinning was close enough. But if they removed driveshaft and it fixed both then I guess it is related. That's crazy that the angles are off, let us know if the shims fix anything. If that's the issue then I see why toyota is dragging their feet, they wouldn't want to have to replace all the axles with proper angles since I couldn't see them telling people to add some shims. Not site how they got that one wrong

 

Have they changed out your leafs for the updated ones? They eliminated about 80% of my rumble strip vibes. There meant to change the pinion angle to help with the vibes.

 

That is exactly what I wanted, but the service adviser is not aware of any updated leaf spring or "kit" for this. I attempted to explain what others here are having done, but without a part number for the springs or a kit or something to reference, they can't look it up. Were you provided with anything from the repair?

 

ill look for my paper work after work bud.

 

I have an update, but I have only read about the first 5 pages of this thread so if someone has also posted this already sorry for repeating. I contacted the dealership today more specifically the service department. I just purchased a 2017 Tacoma TRD OR DCSB with the tech package. My truck was built 8/20/16 in Baja California. I enquired about the rear differential noise that has been referenced here and asked about possibly extending the warranty. I also asked if any one had experienced these problems with vehicles purchased from this dealership. He said they have had a few 15 and 16's come in. No 17's as of yet. He said there was a TSB out and the issue is a bearing within the unit, don't quote me but I think he refered to a carrier bearing. To me this would make sense, it starts gradually and in some cases more than others gets worse with shorter or longer time frames. When it gets "loose" it causes excessive wear the gears and itself for that matter. Toyota is aware of this hence the TSB I was told about. I had a similar problem with a Nissan Frontier, the trans cooler in their radiators was defective and would allow radiator fluid to enter the transmission, if/when that happened the glycol in the radiator fluid would eat the composite on the auto trans clutches up in short order and trash the trans. That was a 6K fix! I tested my fluid with a glycol test kit. I was good to go, Nissan even made a kit to bypass the transmission cooler inside the radiator which was basically a short piece of metal so the hoses entering and leaving the trans could be connected so as to bypass the defective radiator cooler, as there was also an external cooler in front of the radiator. Nissan looked at all the data and must have seen the failure rate was around 100K miles so to avoid a class action lawsuit they extended the warranties out to 80K on the radiators. This got them out of a class action lawsuit and they only had to eat a small percentage of the radiator/trans trashed trucks out there. I watched a video on one that had failed it was interesting to see. Nissan as of my last knowledge still uses the same manufacturer of that radiator. I am not sure if they redesigned the cooler so that it would not fail however. My point is this, sometimes 3rd party parts are defective which will make the larger part they are installed in fail or in Nissan's case destroy a different part altogether. I have a feeling there are a lot of defective bearings out there in these trucks that will need replacing. I hope this is the root of the problem and for every one that has a howler out there they found out what was the cause of the failure and fixed it. After talking to the service tech I have decided to go thru with the purchase of the truck and not back out. I never told the service tech I was on the fence and only came across as concerned and inquiring about the extended warranty I beliee he was honest with me. The dealership seems knowledgeable and willing to fix the issue. After all they are getting paid since it is a TSB now. When I asked about extending the warranty the service manager was a bit perplexed, he said why? It is warrantied to 60K. If I do end up with a howler, I will use the warranty, if it goes south after that I have a good mechanic that can fix it right. I think these are good trucks as I have had a 2004 base model 4 cy 5 speed manual and also a 2007 TRD Sport. Both trucks ran great and never gave me issues. I have searched this problem out online and it seems like there are several generation 2's out there that have this problem also, along with other models which would make sense to me as like all other auto manufacturers they buy in bulk and if they can use a part on several models it is cheaper. Welcome a mass production!

 

Please post this alleged TSB @Hicap239

 

I don't think whoever you talked to knew what they were talking about because a day ago they replaced my whole diff for the howl not a carrier bearing TSB as your advisor alluded too, I don't think there even is one. There is talk of a pinion bearing TSB to go along with new leaf packs to fix the rumble strip issue. But as of now when your service advisor calls Toyota Corp. about the rear diff howl, Toyota recommends replacing the whole unit, no TSB in place as of a day ago. The diff in the 2nd gen is different than the 3rd gen so not the same issue. There are also a lot more reported current 3rd gen owners (some 17 owners) with the howl I think its up to 180 reported. Sounds like he was getting you to buy the truck, rather than legitimate facts and information. Sorry to say.

 

There isn't one. My service advisor called Toyota yesterday about what to do for my diff howl, they said replace the whole unit.

 

You guys beat me to it! I was about to be like "GO BACK TO THE DEALER AND GET THE TSB# SO I CAN CALL MY DEALER FIRST THING IN THE MORNING!!!!!!!!!!!!"

 

Yeah I'm very skeptical, as there are a few folks that are supposed to get in touch with me from Toyota when a fix is released.

I figured I'd give the guy a chance to support his claims though!

 

am I the only one that read his post and think its all wrong?

He said his truck is made in Baja, California?
Aren't they only made in either texas or mexico?

 

San Antonio Texas and Baja (the mexico plant)

 

ah ok.
I read Baja california and thought it was a region of California state.