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

I'm just trying to understand how a heat insulator is going to solve noise issue.

 

It's not.

 

Has anyone replaced their diff or electronic locker or axels or all three with aftermarket? If so does he howling stop?

 

So I decided to change the diff fluid, great weather in Michigan today...

tons of space back there to work if you drop the spare... anyway, it was low... by about 1/2 quart... going through the motions... the Off Road uses 4 quarts and mine ate it all up and it needs a bit more... so get 5 if you are doing it

 

Cool. Let us know if it did anything. What type of fluid did you use?

 

I have asked this before, to no avail. With all the people regearing, I can't believe not one of them has ever had the howl and confirmed it being gone afterwards. It would really narrow things down as far as what's causing it.

 

sorry to repeat a question but thank you for getting me on the same page. I would regear my taco and dump the warranty if I didn't just drop 9.5k on suspension for my '03 is300 and 15k on an LS3 and swap kit for my '93 240.

 

Just started noticing a faint howl on my 2017 OR-AC w/ 1600 miles in the 50-60 range.
Definitely will start monitoring if it changes as miles add up.

 

I got an Sr5 longbed as a loaner while I get my squeaky leafs fixed.

It is brand new with only 1k miles on it. It's a nice truck.... That howls.

It's quieter that mine, but it's definitely there.

 

I think the guys that regeared had theirs go away.

It's shit backlash and bad pinion / gear set up. Toyota just doesn't want to spend the money to fix it.

 

Took mine to the dealer today and they said it was the carrier bearing and they had to ordered it. Said that was probably due to my lift,but they Installed the lift,so it on them. But it's still hard to me believe that carrier bearing went out with only 5000 miles on it!

 

32K on my SR5 4X4 V6. Still quiet.

G.

 

Howl still there after fluid change and top off... just FYI, will wait to see the TSB, it does only happen on 5th and 6th gear for me.

 

Is it because you're usually around 55-60 mph in 5th and 6th gear? The only time im in 4th gear at that speed is when I'm accelerating and you don't hear and howling anyways. Downshift to 4th gear and feather the throttle and you'll hear it slightly over the engine

 

Mine is definitely just as loud in 4th as it is in 5 or 6.

 

I tried to make it howl in 4th and no go, will try on my way home today again. Today was rough, traffic was moving in that (62-65 mph) speed on the ride to work making it very noticeable.

 

Where'd you hear that it was a backlash issue? I have been trying to read through this thread but uhhhh there's a lot.

Edit: not discrediting your claim, backlash means room for vibration which means noise.

 

Heard from an engineer from one of the big three that this may be considered "normal" like a tuner in many trucks, not "right" but not defective, other than the noise, and no catastrophic failure should be expected...

basically, at certain speeds, the differential size, spin and shape causes the "whine" like a whistle, when you blow with pursed lips a certain way. Which is why it only happens when feathering, and not at all points in the range.

Changing the design is the sure fire way of repairing... said these issues are not exclusive to Toyota, and are not super common, but happen still, as we are all experiencing.

Makes sense actually, may not be a flaw other than it's causing hum due to slack it's designed to have. The fact that 6MTs have this happen more often reinforced his comment... maybe a size change in what has the slack is the only solution as it changes the "musical" aspect of the differential... Thursday have a follow up with tech to keep looking into solutions...

just sharing...

 

Its definitely logical. I had a DSM AWD long time ago and the transfer case would make a whine at certain speeds, was told it was "normal" so I lived with it. Owned it till 140k miles and never had issues. Sound never got louder either but was always there.

Crossing fingers its the same case with our trucks.

 

I don't think it occurs more in the 6 speed manuals, I heard it in an automatic I test drove and it was much louder than mine.