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

If your rear diff is smooth running with no chattering or vibrations or anything odd like that, I don't see how it would affect shifting through gears?

Can you explain further? I have a manual as well. Are you talking about the jolt you can get shifting sometimes? Or is it something else?

 

my rear end makes a clunk sound when going between D and R, sometimes. Is that what you mean?

 

He has a manual. If you don't hit the shift just right you can feel a jolt from the rear as the gas is applied when you get into gear. I get it too if I'm at the lower RPM band for the gear im in and I'm not super sensitive on the throttle. That's why I want to know more. A smooth operating differential shouldn't affect changing gears. And the howl isn't causing and serious short term issues, it's just f'ing annoying with the back seat singing to you at 59 mph

 

Update: Toyota had me go back to the dealership. The service manager had me ride with his shop foreman. This guy was extremely knowledgeable and we went on a decent length drive (he drove). He even seemed very, very knowledgeable about the 3rd gen overall which was impressive.

Anyways, he ran it through a variety of speeds and recreated the howling. We got to talking about differentials and what has already been done and he says it is highly unlikely that two differentials would come off the line with an actual serious defect. One originally on my truck and then another down the line as a replacement.

What he actually thinks is happening is that we are hearing a natural harmonic as we "float the gears." He says he believes it is going to come down to more of a sound damping issue more than anything. He said he has personally seen it happen on other trucks in the past when people put camper shells on them and suddenly the sound starts resonating through the camper combined with subpar sound damping in certain models/trims.

He is going to update Toyota on the findings that the new differential still howls and the condition upon which it does. He wants the videos I took too because he says toyota will actually be able to use those to extract what frequency the noise is occurring at to narrow down what it is.

He doesn't believe it is a safety issue but assured me Toyota will be heavily inspecting the returned differentials and will know for sure if it is an actual gear/bearing setup issue or assembly issue but that he would be really surprised if it was.

Like I said he seemed extremely knowledgeable and experienced, I trust his observations, so we will see what happens moving forward. I have never had another car/truck with a noisy differential, or driven one, that didn't have an issue with the differential. But he seemed confident it is a sound damping issue, but is not ruling anything out at this point, just said it would be highly unlikely for Toyota to mess up a differential that bad if it turned out to be a serious diff issue.

I'll keep updating.

 

Well,had new differential installed today at laurel Toyota in Johnstown,pa.today.Good friend's with lead tech.,he pulled rear diff.out of my SR ACESS cab 4x4,and there it was, main pinion bearing fried....He said from what he seen that the rear diff.was NOT set up the way it should have been....what caused it was unknown...there sending it back to Toyota's lab.,keep you guy's updated...Road test proved no whining noise...hope it holds up..time will tell....Doug in Pa.

 

Tech working on my truck thinks the rear diff whine is exhaust note. I need to take a road trip to see your service manager!! Sounds like you are in good hands....

 

Exhaust Whine...Hmmm...that's a good one,i seen with my own eye's the pinion bearing was chewed up big time....Poor set up on diff.think that's whats going on here,could have been low diff.oil like the tranny problem's....

 

Oh yea,Toyota just got hit with a $2000 dollar bill from Laurel Toyota....WoW...maybe they will find fix soon ?

 

Me to...this is getting old...they must think we have nothing else to do but run back and forth to the repair shop,went down that road with my dodge truck....

 

I had a pinion bearing failure on the last truck I owned. I do have to admit that although it whined, it got a lot worse a lot faster than this is. It also whined all the way from low speed to high speed changing in pitch the entire way until it was just a loud whirring noise. Finally it started causing a very high frequency vibration that made my mirrors so blurry I couldn't see out of them properly.

Were you experiencing the same thing as everyone else in this thread? Just feathering the throttle between maybe 50-65 mph and it went away off the gas or as you pressed on the gas? Or were your symptoms slightly different or much worse and over a wider range?

 

I also realize the shop foreman's theory aligns with what smitty said he was told about a fix in the works and that they were looking at differentials and seeing no premature wear. But smitty was never given an indication of what the fix would be.

The shop foreman didn't mention anything about Toyota engineering or hearing of a fix or anything, I am under the impression that everything we talked about today was his view and diagnosis alone. He simply said he would pass the info to Toyota and they should be able to figure it out.

So it is promising, at least, to see his theory align with what smitty was told by Toyota. Assuming the shop foreman truly has not heard of anything or been told anything by Toyota corporate.

 

Yes, I get the jolt too if I don't rev match correctly upon clutch release. Mainly 4-5 and 5-6 if I'm being a bit lazy. Lol, doesn't happen if I'm lettin' it eat though!

Frank

 

This is exactly what I have been wondering while reading these posts for a few months --- is it some sort of artificial harmonic being created through vibrations?

 

It's been almost 1 month now, 1 more to go....if the FTS timeline was correct for a TSB/field fix

 

They test drove my truck today and were able to replicate the howling sound. They changed the diff fluid and are test driving it again.

And they changed the engine oil under Toyota Care. I didn't want this done because we are going wheeling tomorrow but my wife took it in this morning and agreed to it. Ehh

 

Sorry been absent from TW a while now. My 2nd diff started howling after about 200 miles. It is not as loud, but there. It was quiet for 200 miles though. I was in for my 10K service today and talked to the service manager. He called the Field Rep for our area and asked him what he knew. He put him on speaker phone so I could hear. Field rep said Toyota is working with the bearing manufacturer on the pinion bearing. Said the bearing machine finish is in question. Don't know if it is true. Seems we all get some kind of answer that Toyota knows.

 

So the dealership won't let me leave in the vehicle. They serviced it today and test drove for the differential howl. The tech didn't like it so he lifted the truck on the hoist and drove the wheels between 50 and 60 and the noise was much louder. They haven't spoken to Toyota but they would not let me leave in the vehicle. They said it was too much of a liability to allow me to drive it.

They gave me the max allowance for a rental because I told them I needed a truck. They had an Enterprise guy come pick me up. I assume they could not give me a loaner either because they don't have any left or because Toyota hasn't approved any work.

So I don't have a truck now. We were supposed to go on a sweet run tomorow with a Facebook group but that's not possible now.

I'm very sad

 

This is the juiciest 3rd gen issue so far. So many different angles, so many different experiences. I feel like I paid $30k for the privilege of being part of the 3rd gen history books.

 

I didn't add that Toyota told them to change the rear diff fluid. They changed it and test drove it again and it wasn't any better. They will be calling monday morning to get a new differential approved. I hope they can get me a diff quickly so my truck isn't unusable to me for very long. I can only imagine the wait time

I didn't pay 39100 dollars for my truck to sit in the shop while all my friends are on a fun wheeling trip that I was really looking forward to

 

We are the test monkey's for Toyota...still love this truck....carry on my wittle taco friend's,only get's better....