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

I'm thankful for this forum. One week and 205 miles on my '17 and even tho I can't her sh*t anymore, I can her a whistling noise or whine from the rear I believe. Its nice to catch a you tube video of someone recording the noise and it being exactly the same as I heard this morning. I was worried that since I took the front air dam off that it was related to that or something with the transfer case since I tried out the four wheel drive last night, but no, just a sh*tty rear differential where there is no fix. Awesome.

 

Welcome to the club! Rumor and speculation say that a fix may be close. Hopefully you won't have to wait too long.

 

May be used to it, but mine seems to be getting quieter. Don't know why it would though. Maybe I've learned how to drive it without feathering the throttle!

 

Add me to the list.

Would never have heard this without this thread. Have to turn radio off or way down and really try to make it howl at ~55mph. Barely audible and only when feathering throttle over about a 5mph range. My wife was incredulous and thought it was the truck next to us, but it correlated to my throttle inputs.

Doesn't bother me in the slightest now since I have to look for it but I'll be keeping an eye on it. No use in doing anything now since Toyota clearly has no fix currently. Since I've got 2.5yrs+ on my warranty I'm just gonna hang tight.

Smitty can you prepare my crow? I like it medium rare sans feathers...

 

There's no fix because it's the shape of the new rear driveshaft. It doesn't howl when you're on the gas because the front end of the truck lifts and the fluid rotation around the driveshaft is disturbed.

 

Well, I too have the howling diff. Took it into the dealer this morning; got the dreaded call this afternoon: metal shavings in the diff, black fluid. Black fluid! What's going on here? Anyway, the lead tech doesn't want me to drive it, so I'm getting a rental until the part comes in. Service adviser says there are 30+ diffs on backorder! Could be a couple weeks. Will keep you posted with more info.

 

There is nothing wrong with your rear diff. Go pick up your truck.

 

Mine howled even when on the gas. If it was due to something like the shape of the rear driveshaft (which I'm unsure how it would be anyways) then it would howl just as loud day one on the lot. They don't. It develops and gets worse over time. The tech even drove a new one on the lot to verify, per toyota's request, as part of his full diagnosis on mine.

Toyota agreed it wasn't normal, said to replace it.

Also, just curious, what fluid rotates around the rear driveshaft towards the differential?

 

They told me mine could take two weeks but then it only took 2 days. Apparently one was "on the shelf" somewhere in California. I didn't ask any further questions as to what that meant....

 

I know this has been said a lot, but I'll chime in with my experience as well.

At my first service I mentioned a whine in the rear end. Tech said he never heard of that before with the 16 (this was in July). They said the rear diff was bad, they ordered a new assembly. I waited a month, then went in to have it replaced when it arrived. After that, it still did the same thing of course (I hadn't read this thread yet). Took it back in and they called corporate, filed a case or whatever, then said it was a characteristic of the Off Roads. Drove a new one off the lot and it did the same thing.

Oh well, I really don't mind it. Just wanted to make sure it wasn't gonna fail on me.

 

Air is a fluid, they will all howl when the whistle vortex is present. And all the original diffs they've taken to the lab have been fully functional.

 

So, you're saying this howling is benign and is NOT an indicator of gear wear or other mechanical issue with the differential?

I really do hope that you're correct about that, but why is Toyota replacing them if that's the case?

 

Toyota isn't replacing them, dealerships are throwing parts at the problem. There's likely still a disconnect between headquarters, regional reps, and dealers. Like smitty said, the dealer has to put a name on the problem to order a replacement. "Rear diff failure or wear" and they aren't busting the originals open and inspecting them at the dealer. The 8" rear axle is a carry over from 2nd gens (now they howl in 3rd gens), the driveshafts were redesigned for 2016. This was all covered a handful of pages back.

 

Almost everyone complaining about noise has an off-road. Which has the new 8.75" with the internal locker actuator.

 

The whistle vortex? Is this real life?

 

I wonder if it's just something with the redesign. Like new shape or something, and if when they tested the older ones it was completely fine.

I know in another thread @Aussiek2000 mentioned it could be the backlash could be true.

As annoying as a howling might be if its not a mechanical issue and just an annoying sound thats not that bad. Eases my mind about buying one at least. But it also only seems to be getting reported for the US models not the Canadian? Not sure why.

 

One thing is for sure, most tromp on Toyota even when they don't know what the real problem actually is or could be.

 

Well, add me to the list. My radio was off as I was leaving work today and finally noticed mine howling.

 

Mine's now doing it anywhere from 35-70....