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

I do sympathize with your dilemma. That is the reason why I commented on this thread, and offered some suggestions that go ignored by those who just want to rant and make more noise than the noise itself.

Please don’t take it personal, it’s not on you.

I quoted you as in general principal to address others that are aggressively and constantly posting nonsense to advance their agenda against this vehicle.

I’ve been in all aspects of the servicing side of the industry for over 40 years and there’s not much that can get by me. I have seen identical F-150’s and Rams where one was howling like crazy, and some of the time it was an axle bearing going out.
other times it was mud tires in rear with A/T in front, or mismatched rear tire brands (Goodyear on left Firestone on right) and/or mismatch tire sizes. On more rare occasions, it was a pinion bearing or gear going out or out of specs.

If the noise in your case is that loud in comparison to all the rest on the dealer’s lot, then something is off. You say the diff was totally replaced, so we know it’s not that.

But what about the axle bearings? Anyone check or replace them?
And what about the load? Do you occasionally you carry excessive loads such as construction materials or debris?

These are just some of the things we can’t possibly see on a forum, but your dealer might notice or ask.

If the noise is just common and you can’t stand it, simple things like putting a healthy coat of black automotive paint on the rear axle may just tip the balance.
But you can also spray undercoating on the top of the bed above the rear axle rear and under the cab.
Also if you remove the rear seats, you can get some cheap insulation from home cheapo at the hvac isle, or attic isle. That should also help minimize, not eliminate the noise. The axle will always make some noise.

These are simple cheap suggestion, and if you’re honestly trying to make life a little more quiet inside the cabin, you’ll try it and don’t even have to thank me for just trying to help you and other fellow taco lovers.

Hope that helps

Cheers!

 

Not by a long shot, I'm just a fellow enthusiast who wants to know about my truck and how to maintain it.
TOYOTA prob hates me!

Cheers

 

Right on.

My next step is aals for the rear. People have had some success with that. Might break up the resonance side of the issue.

Other than that this truck has trained me not to feather the throttle at any speed between 45-60mph.

Besides the howl it’s been a great truck!

 

I was mad at Toyota because I got stuck with a truck nobody would buy from me because of the diff howl.

Who would buy a truck with 1000 miles on it that howled loudly when they could go get one that didn’t howl?

Answer: nobody.

 

I too I’m mad at TOYOTA (I J/K) too for the Atkins system and tick tack and chirping noises it makes during the cleaning cycles. It’s terrible!

One of my sons drives a BMW and the other day we were parked side by side and he asked me what was wrong with all that noise it was making (like a mini diesel) and I could hardly hear his running. I tell you I was so embarrassed, I don’t wanna go there.

And then I got to thinking, what’s going to happen when I go to sell it? So I though, I know, I’ll sell it when its not on the cleaning cycle!

NOT!

So the then I had a better idea, I’ll just pass it on to one of the grandsons and get a Camry because no way people are gonna believe the Atkins cleaning cycle noise is normal if I try to sell it, even though it’s normal.

So glad I love my truck for its trouble free performance and the good gas mileage. I don’t really need to unload it.

Does anyone have a better idea? :/

Cheers



Edit: PS, ask me if I want to trade for a BMW

 

OVTune - deletes the Atkinson Bs, better mileage and more consistent torque and throttle mapping

Fuel injector cleaner - every 5000 miles. Have 25k on my truck and it's damn near whisper quiet

 

Damm!

Why can't these people work for TOYOTA??

Oh wait...If this was GM or Ford, there would be a SR V.P. behind it moonlighting, hm...




Edit:

That's good to know dude. I did not know that, thanks for the (alternative idea) info.

 

It’s the 4 hour road trips on two lane at 60mph (give or take 4mph) that got to be annoying with the howl. It was like someone blowing a kazoo for 4 hours in the back seat.

I really do wish I was one of you guys that could tolerate the sound. Woulda saved me a few thousand dollars. I’m now convinced the sound is harmless in most cases. And the truck will be fine forever. That’s great for whoever ended up with it, although I sincerely hope it wasn’t one of you guys.

I have no doubt whoever bought that truck ended up severely disappointed if they didn’t do a thorough test drive before purchase.

 

I suppose that would depend on how problematic their previous vehicle was. I mean, if it was found on the road dead each day, they’d be happier they could get to work or school on time everyday as they can always turn on the entune volume.

And to be honest, if it’s annoying noise it can be dealt with rather cheaply.

A major mechanical failure on the other hand would be a deal breaker and we don’t have that going.

On the positive side, the dealers always seem to be able to take it off your hands and move or sell anything with a coat of paint and tires on it, so there’s that.

But noise of any kind is no bueno.

Cheers!

 

Call me crazy but I actually like the strange sounds from the Atkinson engine. It's reassuring knowing my valves are taking a shower.

 

I have just the thing for you, You'll love it

 

Has anyone solved this with a layer of dynamat? I don't feel like this resonance would be as easy to fix as a trunk rattle.

 

I'm wondering if adding weights/mass to the rear frame rails (in the C sections) might help with this. The frame is helping to transmit the noise to the cabin, so adding mass to it should in theory change the resonance characteristics.

I might experiment with this sometime. That and maybe just wrapping the entire rear axle and pumpkin in dynamat

 

Many home HVAC compressors have a two layer foam/vinyl jacket or cover for noise reduction.

There’s a TW member that makes custom fitted upholstery pieces for the Tacoma interior.

If we could just get him to make a triple layer-dynamat, foam, MLV- jacket to completely cover the rear dif.

I’ve thought about wrapping the pumpkin in multiple layers of different materials and duct tape just to see if it would make a difference.

I used soft/thick exercise mat over Boom Mat applied to rear wall. That helped to quiet it down a little.
Also placed pipe insulation outside between cab and bed.

Toyota replaced my rear springs and cab isolators at 3,000 miles from new. That helped a bit also.

 

In 75 Datsun added a 10 lb weight to their 240z differentials.....my 72 didn't have one and it wasn't much worse than what I have now. You sit right above them and there is no sound deadening.

 

Some Fortuner models with the 8.75/8.8" come with a damper. No idea if this will work for the Tacoma, or if it will even bolt on... but generally these are put place to deal with vibration and the associated noise it may cause.

 

interesting

 

My dealership isn't willing to try adding the TSB specific dynamic damper as I fall outside of the affected VIN number range.

 

What was the response from Toyota corporate when you told them the above?

 

I didn't hear back from the dealership until late in the day. I will be calling them tomorrow.