[SOLVED] 440Hz Tone between 35-45MPH ......(Link to Sound file)

I wasn't hearing alot of unusual noises & def. don't think it's pinion bearing in diff. , those bastards howl like hell when decelerating...

 

I dont know, to me sounded exactly like diff when you spin it when you working on it. When they howl really load than they completely out of the tolerance, but if they starting to get too much backlash they get noisier.
I think I have thrid member out of the truck I may record sound and post in 2gen section if people interested.

 

But like you mentioned about checking fluids, people would be shocked to know how many new vehicles get thru the new car prep (before selling to public) with dry (or almost dry)diffs & other important components that require alot of lube...

 

Haha love STS's some of my best friends.

 

You are in the unique position to put of delivery until it is resolved.
There are quite a few of us who are trying to tackle this issue. We just want to know the source. The more people take their vehicles in, the more attention the issue will get. Even if it's "normal" we are entitled to know what the source is as none of us had this noise on the Gen 2. I am either getting used to it or its getting quieter. Make them file a service ticket. Bob in Florida has a Toyota tech coming friday to hear his. He has our VIN numbers and is working hard to make his $40,000 Limited fun to drive again,

 

Rear diff has redline in it, last changed 30k ago. Still full as of one month ago when I checked it during my last oil change. Truck has 154k miles on it

I've had this truck 3 years and this noise has always been there since I got it. When going fast it's louder when cold, like if I get on the freeway within 5 minutes of a cold start I can hear it at speed for a couple minutes, but overall it hasn't worsened. It's always there 35-40 mph though, cold or hot, and it's really quiet at that speed. My 09 v6 I had before also howled at 40 mph, but it was much much louder (like in the OP's soundfile, maybe more) and I sold that one with just 53k on it. We had a TSB for whining diffs at one point didn't we? I can see how. They're not quiet

My default position has always been that if it gets worse I'd be giving ECSG a call and just put a new third in. I want to switch to a Tundra soon so it may never happen on my watch.

 

The service tech last night heard the noise when we went for a ride, he was going to put in a service ticket today.

 

i gotta ask....

how did you know that it was A 440?

 

Yeah so that definitely sounds like a diff howling and if you don't push it its goign to last. Since you have 2.7 you not going to tow anything heavy, so only concern is when you off-roading not to spin wheels and not pull backwards.

You know your diff probably just needs backlash adjustment done, (a shim or two) maybe new crush sleeve.

 

I don't think it is the differential since it doesn't seem to change with speed; but, just for fun I decided to see what frequency to expect if it was the diff.

For both the 3.91 and the 4.30 rear ends, at 40 mph teeth are meshing at 326 Hz (since both ring gears have 43 teeth). You would have to be going 54 mph to get to 440 Hz.

 

Well OP...I drove mine today for 10 miles w/out the radio between 35-45 MPH and I didn't hear anything...No wind, No high pitched anything!
I just picked it up yesterday...TRD Sport 4x2 DC SB

 

weird...I just looked up whit exact same A 440 video today...but for completely different reasons.

 

@bob1946 Any update from the Toyota tech?

 

Thanks for the update @bob1946

I'm bringing mine in next week for sure to get a case report!

 

YES do bring it in. We have Toyota looking at it. My dealer has a Service ticket in. I am going in with Bobs Paperwork so they can see Toyota has confirmed the noise. We are gaining ground on this. I thought it was the driveshaft as well....

 

I had to call in my young guns to listen for the sound. They say hearing is the first to go! I had my daughter listen to the sound file TacoBella so kindly provided, then we went for a ride. She sat in the back seat and listened for "the sound" but didn't hear it. We varied the speeds from 35-45 and other than the noise of the tires on the pavement and some wind noise, nothing. Curious to see what this is and how widespread it might be.

 

http://www.gearsolutions.com/article/detail/6163/eliminating-gear-whine

 

Hmm. If you hit the drive shaft with something, does it ring at the same frequency?

But, if it's the drive shaft shouldn't long beds have a different frequency?

 

Good question. If a drive shaft is out of balance it will cause a howl at those speeds. drive Shafts have to be balanced. I called the drive shaft out awhile ago.

 

Would be nice if someone had access to a dyno. That would eliminate possibly of wind noise.