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

@ryan760 I have been wondering if regearing fixes this noise. I had assumed that would fix it since the pinion gear would be a completely different size, and the Toyota ring/pinion would be removed completely.

Thanks for crushing my hopes and dreams.





I'm kidding. Sort of.

 

It clearly doesn't eliminate it. I can totally hear it in the video... especially during the 5 or so seconds after the 7:47 mark. It peaks, then drops offs as he decelerates. What im hearing isn't tire noise.

If you keep watching, he comes to a stop, then starts to accelerate again... quiet, quiet, quiet, then once he hits around 60 that distinct tone comes right back. I'm guessing his speed range is different because of the different gearing.

In my opinion this is somewhat good news as it lends credibility to the harmless NVH argument. But bad news in that I don't know how the hell to fix it yet lol

 

Thus far some have claimed that fluid film on the leafs dose it, others have insulated the back cab wall and stuffed foam in the cab vents, lifting the trucks seems to have worked for a few, and some have changed their differential fluid to Red Line claiming that got rid of it.

All of these attempts seem to have inconsistent results. I had a 17 and now a 19, both of which whined between 50 and 60. The 17, I had the TSB preformed with no difference, and then the differential replaced which quieted it down a little bit. My 19 I’ve had the differential replaced with little change. A bit quieter if anything. I did the fluid film thing with no change, and I might give the Red Line a try, but not getting hopes up.

Where I live the traffic flow is 90% 50 to 60 mph, so it’s torture. Maybe the only fix is for Toyota to stop using Hino differentials.

 

Fixxxxx meeeeee. Lol. We should all just keep bothering the piss out of Toyota until it's solved. I mean, in my Ford experience it only took them 4-5 years to acknowledge and implement a fix for their freezing door latch issues on the newest F150 model (and probably super duty as well). Lol. I believe they should implement their fix pre-production, but to my knowledgeable they haven't yet.

Point is all manufacturers have ongoing issues to solve. I'm just encouraging more "squeaky wheels" for Toyota to hear and take notice of. Haha

 

Definitely a mixed bag then. Your personal experience included. Thanks for chiming in. Interesting you say changing diff fluid worked for some. Let us know if it works for you! I agree its torture when youre stuck in that 50-60 mph range. I dont usually drive roads with that speed for very long thankfully. And if the speed limit is 50 im doing 60... and I can only hope the officer who stops me also owns a Tacoma haha

 

I think the real problem lies in the design of the axle tubes and diff cover. Too much vibration is transferred through them to the springs. Might explain why using entirely different gears doesn't make the issue go away.

Going to try experimenting adding weighted magnets to various parts of the truck.... on the rear leafs, axle tubes, frame rails... see if that changes anything.

 

Anyone else notice that the howl is more prominent when going downhill?

 

Have not noticed. Not usually going down any significant hills at those speeds where i normally drive.

Has anyone had success eliminating this noise with an Add A Leaf rear lift? Etc

 

Probably because less weight it on the real axle while going downhill and so it can vibrate more.

 

Due for 30k service soon, going to talk to the dealer techs about the whine. See what they say.

 

All terrain or mud tires help greatly. Noise for noise

 

Does it in all M/T gears, just harder to hear over the roar of the engine

it’s because you’re in that sweet spot of juuuuust enough throttle to get the howl

 

Mine would increase going downhill and then dissipate when I started going back uphill.

 

Dropped the truck off today, should be picking it up Tuesday. If the new diff doesn’t howl I’ll let you all know.

 

Let us know what happens either way. Good luck.

 

Hopefully it helps. The two differentials I had replaced only lowered the sound, but it was still there. I agree with the AT tire suggestion. Overpowering the noise maybe the only consistent solution. I still have hope that one day I will browse TW and someone will have a solid fix.

 

Just checked my owners app, the service notes just updated for my 2020 diff replacement.

 

This was exactly what I was told but my report was more vague. Basically I was told the same thing but the report was very watered down. I hope this works out for you. Best of luck.

 

Ugh, that's not good.

Please keep us updated if the noise returns

 

The details from my second differential said something along the lines of “excessive play in ring & pinion causing whine between 50 and 60 mph” ..... bla bla bla, they have all whined. I think they have to put something to justify the work, even if its BS.