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

I really hope this one works out for you. Until this issue is truly fixed I’m going to stay away. Like so many others, I’ve driven Tacos for a long time but my 17 almost drove me nuts. Best of luck and hope this one fixes the issue for you.

 

New fluid didn't help. Not even thicker gear oil. No change at all.

 

If you can, we would be interested in pics or description of what they say about your old diff. I've heard a lot of stories on here about people taking their diffs in to get examined, but never see any pics or evidence.

Also, I'm curious about your 2018... what model was it? any mods? stock tires?

 

The diff is not torn down and analyzed at the dealer. They package it up as it comes out of the truck to return to Toyota who then sends it to their supplier for the warranty.
I’ll be sure to get lots of pictures comparing both. I’ve also requested to see the drain plug magnet before it is cleaned off. I’m curious as to how much metal will be there after 6000 miles.
My 2018 and 2020 are optioned exactly the same except for the color. They are both TRD off-road double cab trucks. The 2018 had 2”/1” spacer/block lift and 255s for the last 5k miles I had it. That truck was silent before and after the lift. I’m installing 6112/5160s, Icon AAL and 255s to the 2020 on Saturday.

 

I hope it helps, but not likely. Had my diff replaced and was silent for about 1000 miles then started howling again. However, it does not howl as bad as the original...for now. I will just live with this little annoyance as there is no evidence I have seen that the differential will fail due to the howl.

 

Anyone here regeared with aftermarket gears and solved the howl as a side effect?

 

Just got done riding in my uncles 2019 TRD Off-road DCSB. His howls on both deceleration and acceleration between 53-59. I didn’t know they could howl on acceleration, but it was clear as day. He also has a bed mat and a bed cover on it, too. It’s not as loud as mine (volume 30+), but it does it through that range no matter what. He is pretty deaf from machine work and doesn’t notice it ha I imagine most trucks have the howl and some people just aren’t able to hear it like him. Lucky them!

 

Mine howls loudest around 57-58 mph on light acceleration to maintain your speed. It howls between 50-65 mph altogether, but loudest at the first speed range I listed. It's noticeably louder with rear seats folded flat which is unfortunately how I like to ride around. I use the back seat for cargo, not people.

 

Mine howls on acceleration too, exact same speed range as your Uncle's. Quiet as a mouse on decel though.

 

Has anyone installed dynomat insulation or the like?

I find that just folding my seats back into the normal position makes a noticeable improvement for now.

 

I'm curious too. If others have noticed an improvement particularly with reducing the howl, even if only 20%, that might be enough to make me consider doing it.

 

I might end up doing this just to lessen some road noise as well. It's on my list of ideas for the truck.

 

It is my understanding that it has not helped much, which surprises me. You would think any additional insulation would help but it doesn’t seem thin this case. I wonder if @nDub recalls? Either way, I’m pretty sure most everything has been tried.

 

Hard to believe dynomat wouldn't help when just flipping my seats to the normal position makes a noticeable difference, not nearly as loud and then only noticeable at a narrower speed range.

 

I have been on this thread since Smitty started it and unfortunately it does not seem to. Now, can it help some? I’m sure it would help a little, but many have tried. Looking back I wish I had just stuck on mud tires and not worried with it.

 

Also on "the list" so I'm not too mad about the howl... yet. Lol

 

I think @trazerr did, maybe.

 

You are correct. I put Noico 80mil under the storage compartments, rear seats, and halfway up the back wall. At the same time I crammed egg foam and other thick foam into the C pillars. Also put foam into the body mount bolt access under the rear seats. It didn’t really help too much.. the TSB body mounts helped the most.

 

Thanks, I knew it was one of you but couldn’t recall which one!

 

I'm gonna assume my 2020 doesn't need new TSB body mounts? Or maybe it does and not enough people have complained yet lol