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

Good to know. Thanks!

 

There was another guy in another thread that regeared to 4.88. He has a thread about the whole ordeal. He didn't mention a howl before, but that doesn't necessarily mean that it wasn't there. He mentioned after the regear that there is significant howling.

I don't take that to mean that all rears howl in our configuration. It's just an observation.

I replaced the 3.91 rear end in my 4Runner with a complete 3rd from ECGS. The replacement howled under the same scenario as my new Tacoma does. They replaced it with another and the second one that I got from ECGS is silent and I'm happy.

I freely admit that I only have a broad understanding of how a differential works and have no idea how to properly set one up. With that said, my experience with my 4Runner is so similar to what I'm going through now with my Tacoma that I'm personally convinced that it is actually the differential making the noise. Also, if a competent gear shop like ECGS can send out a brand new replacement that howls from day one, then think of how hard it must be for Joe Blow the factory worker to turn out hundreds of them a day and do them all right while his three bosses are pushing him to assemble even more than he did yesterday. There's bound to be a high percentage of incorrectly set up differentials.

 

Well still here. 3 hours later. Service manager, service foreman, my wife, and I all drove the truck on the highway. Manager thought it wasn't going to make a noise....

Driving a new one now

 

Man, it seems like you are always at the dealer! They should offer you a room and/or an office there.

 

I hope the dealer you're at at least has good coffee.
The one I was at on the weekend for my test drive had shit coffee.

Hope they finally come up with something to fix yours though.
Really sorry to hear mate.

 

We drove a 2017 DCSB OR 4x4 and it make the same howling sound but at different times while driving. It was more faint but it was still there. I now assume that this is an issue everyone has and people just aren't noticing it because they don't drive that slow on the highway.

We will be calling corporate tomorrow. The service manager is typing up a storm right now doing documentation

He also said that because of the shavings in the diff the first time, that original diff was about to 'let go'. Hmm

 

This may be a dumb idea but I checked my cold rear diff.(sitting of 2 days ) for oil level . It was never under water etc.
I heard a air whooshing sound when i took off the level cap/ bolt. could not tell if it was vacuum or pressure. Is it possible that the howling problem stems from a faulty breather valve causing a pressure problem not allowing the oil to lube the bearings ? Or, simply air escaping a faulty valve creating a howling sound ?
PS I have a very quite howling when feathering between 50 and 60 mph.

 

Not a dumb idea. Anyone have the howl with the diff breather mod? I would think this mod would rule out a faulty breather

 

Anybody have the mod that removed the original valve to extend a breather mod ?
this could rule out the breather for sure .

 

If Toyota is reading, I never had a diff breather installed.... but no, it always howled with or without it

 

There is a factory diff breather right on the diff ?. the mod was to extend it to a higher location via tubing.

 

The factory unit is not a breather. It only exhales. It doesn't let any air in

 

Well then can it be set to hold too much pressure in if it makes a pressure relief sound when opening the fill cap? Could this still be a problem for the howl ?

 

it's not the problem

'people' with diff breathers also have the howl

 

I just want to know , do people that have modified the rear diff breather location by relocating the end of the tubing to make it higher from the diff , replace the the original diff breather with a different one where ever they put it ?

 

'they' replace the breather with a filter and put it behind the brake light or in the cargo box....

 

Ok , then it is not the problem . I thought they just extended the tubing upwards and added a filter .

 

that's what 'they' do. what are you talking about?

 

oh, it's not a filter. It's a metal tube with a cap on the end. 'they' replace that with a filter