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

I concur just as loud in 4hi. Nuts

 

I tried the same thing. No difference. Bummer.

 

Yes, that was my complaint and in all fairness to the dealership, they stepped up and agreed to fix it. We shall see if it actually helps....

 

I have noticed when it's below 40 degrees my replaced rear diff noise is quieter. At 30 degrees I can't hear it. Today it's 59°and it's back, very annoying.

 

That is so strange as since the weather has gotten colder my truck has got louder, go figure.

 

Exactly my thoughts too! I could barely hear it in the summer, if at all some days. Now that its gotten colder---I'm hearing it again. Maybe its viscosity of the diff fluid being thicker when cold? I have no idea...

 

Mine too...plus at lower speeds I hear a cyclical whirring. Most notable when I am coasting to a stop. Sounds like the R&P have some run-out or something and the mesh changes throughout the axle rotation. Not sure if it is at the pinion speed or axle speed.

 

Mine is quieter now that we are getting into freezing temps at night.

Not sure why.

I think after a few miles the fluids in the diff would be up to temp and it wouldn’t matter what the outside temps are.

I wonder if it’s a problem with these non greasable rear driveline u-joints. Anyone with these greasable u-joints have this problem?

Mine definitely don’t have zerk fittings.

 

probably cause the oil thickened up due to the cold weather. Toyota specs out a very thin 75w85 gl5 gear oil to get more MPGs my 2nd GEN also was specs at using it and when I did my 30k maintainence I noticed the 75w85 was very thin/watery as compared to a 75w90 mobil1 that I had on hand. the next 60k interval I will be using a 75w90 gl5 the other seems too thin, this could be why your howling noise is coming from.

 

Just spitballing here...
Temp inversions causing sound to 'bend' upward or downward, propegating further or less, depending on the inversion.

 

Same boat. Not enough research done on the whirring noise - does it seem to mirror wheel speed to you? It seems barely audible outside the truck but super obvious inside.

OA

 

I guarantee they will be inspected for abnormal wear. A growing heap of "scrapped differentials" throws big alarms in Toyota's lean manufacturing world. They most definitely will be looking at whether it is a legitimate problem or not. My concern has always been diff howls, goes back, gets inspected, no abnormal wear, ok diff now becomes a warranty replacement item for the next person who needs a diff replacement.

Now, whether they decide it is a big enough issue to address depends on a lot more than the fact that it is annoying to the "select few" of us in this thread.

I'm not even 100% convinced it was the diff itself, i always wondered if it had to do with the pinion angle. I swore up and down the noise went in and out as the angle changed when I was going over rolling bumps on the highway.

 

I wonder if some of the howling diffs taken out of one truck find their way into another truck as a replacement....just a thought.

 

Seems more like wheel speed than pinion speed to me. Pinion spins essentially 4x faster than wheels....would expect higher frequency than I am hearing if it was pinion speed.

 

Agreed. My guess was something after the CV shaft. Hopefully other folks come forward with this one too.

OA

 

Just got my monthly email from corporate Toyota.

Still no TSB for the rear end howling.

Bummer.


To be fair my person said they’d keep me in the loop at least monthly and they have been true to their word. So there’s that.

 

Hello TW! Long time lurker, first time poster.

I just had my '17 DCLB in for it's 5k service and made sure to mention the issue. Mine has been doing it since day 1 and seems to make the noise between 50-55 when you are decelerating. The first time I was in, they replaced my door seals which clearly didn't help. I went back and had a service manager go with me and he knew right away what it was. He said his lead tech had told him to keep an eye out for this because Toyota had narrowed it down to the tempering of the bearings(best of my recollection) in the rear diff. Currently, I'm waiting for my new differential to come in and we'll go from there. Love the truck so far, hopefully Toyota can get it's 3rd gen growing pains worked out. I'll keep y'all posted.

 

I'm happy to hear that Toyota is working on it, and that you get a new diff. For most here, they seem to deny it's a problem. I doubt they will ever admit it, but hopefully the will make changes to eliminate it in the future.

 

This is what I was told today. A panel to hush the actual problem.

 

Sorry. That's only for the manual trans, and I can confirm it does nothing to affect the noise everyone is talking about in this thread.