Rear Differential Noise

Was on a road trip Friday, wife was sleeping, so I had the music off. Probably the first time I've driven the truck without music. Anyway, on the freeway, I was running around 70-75, and noticed when I took my foot off the accelerator to coast, I heard a very soft "howling" or "grinding" type sound from the rear end. If I accelerate slightly, it goes away; take my foot off the accelerator completely, it makes the noise. Seems to only do it at higher speeds, but the sound is very noticeable. You can actually hear it over the radio too.

I don't know if this is related to the 50mph-60mph throttle-feathering issue or not. Anyone else have a similar issue? Cause? Remedy?

Thanks!

 

Normal

 

Think I read somewhere that its related to rear diff and changing your diff fluid might help.

 

I changed the rear diff oil to a 75/110 Synthetic, and it made a good reduction in noise.

 

Seriously?

 

Was there a full moon that day?

 

@Itchyfeet is always serious .

 

Yes. It’s normal. If you bothered searching you’d find a hundred billion threads on gear whine.

 

Mine has a very faint “howl” when feathering the throttle at 55-60. Can barely hear it with the music is off, does not bother me one bit. Apparently some tacos diffs howl pretty loud. I have 3 buddies with tacos and they don’t have any issues with the rear diff.

 

I changed mine to redline and the noise did not change one bit. I mentioned earlier that it’s very faint, doesn’t bother me at all.

 

I don't know that I'd call it normal. That would imply that the sound is intentional and part of the design. I think a better word would be common.

OP, mine does it too. Many, probably even most have it to one degree or another. It's annoying as hell, it shouldn't happen, but it's not a sign that something is seriously wrong.

 

Rear tire balancing issue????

 

Now a hundred billion and one.

Mine is very faint and doesn't bother me, but I have tinnitus so it's just another pitch to me.

 

Its the same on a buddies 2019 trd or. My 2020 sr5 is just over 10k miles....still very quiet no matter what speed.

 

I searched and read a bunch of threads, but all were related to 4x4 trucks. It seems the feathering issue is also related to 4x4's from what I can tell. If it's normal (in a different sense), or common, and there's no chance of mechanical failure, I'll live with it. 95% of my driving is in town anyway, so it won't intrude much. Thanks for the info.