[SOLVED] Howling noise between 35-45

Just running a bead of silicone around the holes on the outside should be enough to get rid of the noise without affecting drainage. Or the plugs discussed with a small hole drilled.

 

I feel like there is a lot of confusing information on this thread about the actual size of the holes. So, for the record, on my TRD OR the 11/16" plugs were too small to for the top hole that is to be plugged. So now I have an 11/16" plug inside my arm that's likely going to be bouncing around in there for the rest of the vehicle's life. Annoying.

The 9/16" plugs work great for the front two holes.

Anyone know the actual size of the big(ger) top hole?

 

Ha I did the same thing. I have a plastic plug inside the LCA. It will dry up and turn to powder. Not worried about it. I am still using tape on top and 9/16s on the lower

 

Not sure a skid plate would work with the lower Air dam. I would not want to remove the air dam so the grommets,tape,silicone, and plugs do the job.

 

It'll dry up and turn to powder? Really? I thought the plastic was pretty resilient, what am I missing?

I still want to know what size plug I should get for the bigger hole(s), I'll need to go under and measure it.

 

Metalnut, Here is my post from several pages back

https://www.tacomaworld.com/threads/solved-howling-noise-between-35-45.410480/page-4#post-11582868

I used 9/16" for the lower holes. And 3/4" for the top hole (but I don't think this plug is needed at all).

Hope that helps,
Ed

 

I crawled under the DCOR yesterday to tape the holes on a particularly windy day. I could hear the howl resonating from under the truck with each gust of wind even with the truck in park and the motor off (definitely not a driveline noise). I taped 6 holes (3 on each side) on the LCA: the one on top and the two closest to the front bumper as recommended in this thread. With each strip of aluminum tape covering each hole, I could hear a decrease in the volume of the howl. By the 6th hole, there was still a subtle howl, which made me nervous that perhaps my howl was different than the one in this thread. But driving to work this morning, the howl was nearly imperceptible in the cab of the truck. I think it's still there to some degree, but barely noticeable. I suspect if I taped all holes, the noise would be completely gone. But as others have mentioned, I'm nervous about proper drainage and rust. Thanks for the fix.

 

With all the holes Taped, I doubt much water would get in there. The LCA is thick and I suspect those are forging holes. I am looking to plug the top and design an air dam for each LCA Something simple to change the direction of air well under the holes. Maybe a silicon bead on the leading edges of the holes as well.

I shoved a cap inside one of the LCAs LOL Can't hear it but the heat here will dry that plastic out and at least break it up. Plastic goes brittle here in the heat.

 

Finally got my truck, been windy here last few days, and I finally heard what all the fuss is about.

 

I live in a very windy region of the U.S. and actually pulled over after experiencing this noise to inspect my front left wheel. Got back in the truck scratching my head and wondered for a week what was going on. Easy fix thanks to your post and the investigative work of the diligent TW members! Thank you all!

 

Just wanted to give an update / heads up on my OR. I had plugged all the holes except the lowest bigger hole (planned to leave that for a drain), and was still getting the howl in windy conditions.

I put another plug in that lowest, larger hole and it appears to have solved it.

Been in a lot on wind and snowy conditions the past couple weeks and no trace of the howl.

So if you have an OR model, or pull your air dam, you may need to plug all the holes.

 

I have an OR and plugged only the 3 holes recommended by the OP and haven't heard the howl since. Are you saying you did the same without any improvement then plugged the remaining holes and ultimately the bottom hole?

 

Yes, exactly....

 

Interesting, thank you for the heads up.

 

Mine cleared up at 35-45 mph, now at 57-60 I hear it on the passenger side. My holes are bigger too. There doesn't seem to be much standardization on these holes.

 

I plugged all but the higher smaller hole. Was under my truck yesterday and the wind blew... Still howling.

I can hear it as well when driving. Might need to try taping the bigger top holes... The plug sizes listed earlier didn't work for my top holes, only the bottom

 

The next place I was going to try was the vertical holes in the frame where the lower control arms bolt up to. That might be something to try next if plugging the control arms doesn't work for you.

 

I'm seriously about to get some expandafoam..... LOL

 

Does anyone smarter than me see ANY potential issues with a waterproof/outdoor expand foam product?

 

To follow up on my own post for future readers... you want two 9/16" plugs, one 11/16" plug and one 3/4" plug per side. The 3/4" goes in the top forward hole. The two 9/16" go in the bottom forward holes. The 11/16" goes in the middle bottom hole. I drilled small drainage holes in the bottom plugs, but left the top plug whole.