Howl from rear differential

Lol joe whats the biggest tire size i can fit on my 4th gen without rubbing…..

 

Howling differential is a classic rerun that originally aired back in ‘16.

I just can’t wait for the the first Gen4 owner who complains about a strange whistling noise emanating from under the hood of his iforce turbo 4 when he accelerates…

 

Put in Amsoil 75w-110. It’ll quiet a bit.

 

I am one for three, we have a 22 OffRoad with 8k miles that howles like like a banshee and a 23 Sport 1.8k miles that is whisper quiet along with a 22 long bed Offroad 7k miles that is also super quiet. My problem is that as the king of coasting... I am a cheapskate and spend most of my time hypermilling trying to achieve the high score for mpg. If I did not know better I would think that they use straight cut gears

So for as much as I keep hearing that it is not a problem I have to wonder why I have 2 perfectly good quiet Tacoma and one that is remarkably whining like all get out.

 

Nope. Barking up the wrong tree. It is a harmonic, not caused by shitty gear lash. Believe me.

 

Fucking no it won't. No magic in that bottle.

 

When theoreticians get angry with empiricists…

 

i used the 90 weight with no howl. but i also changed it at 500 miles

 

Ok, so if it is harmonics I would think that a hollow drive shaft could amplify or cause the noise. Would it be possible to dampen the u-joint connection to the differential with an isolation layer of rubber or simi soft plastic. And just curious why it only happens on one of three identical trucks.

 

The Toyota TSB adds rear cabin insulation and I think spring isolators.
As to why? I design machines for a living and when you put 10K of parts together, no one will ever be identical.