How to sound deaden the interior of your TJ

[Tob]

You can start with 25% coverage on the tub. Cover the large flat sections first, those are the ones that produce the most resonance. If you knock on it with your knuckles and it sounds like a drum, cover it. For heat resistance I just use attic flash insulation, the stuff that looks like puffy aluminum foil. A layer of that under my carpet and my feet aren't cooked in the summer.

Resonix sells just about everything for sound treatment. Closed cell foam, full sheets of sound deadener, CLD (which is what we're discussing, like Noico and Dynamat), butyl rope, cloth tape. Check out the website, there's a lot of information about what each product does and how to use it properly.

I'm steadily sound deadening mine. Making my own headliners made a HUGE change in the noise.

Resonix CLD is $12.50 per sq ft! . No way Jose. It can’t be that much better.

Dynamat: $6.39 per sq ft

Siless: $1.72 per sq ft

 

[Tob]

Alright, I’ll be going with a two layer system - 80 mil CLD and another layer on top. Siless has two recommended options: a 157 mil closed cell PE foam, or a 200 mil 3-layer hybrid - 50 mil butyl mastic, 100 mil closed cell PE foam, and 50 mil mass-loaded membrane. I’m on the fence here. I would think the 157 mil PE foam gives better heat insulation while the hybrid gives better sound insulation.

Any thoughts on one vs the other for a second layer?

 

[JMT]

If you could squirt a liquid rubber or a product like Vulkem between the tub and supports it would stop a bunch. Then run a good bead several inches apart on all the flat panels. That would deadening even more. Somewhere there is going to be a diminishing return.

Alright, I’ll be going with a two layer system - 80 mil CLD and another layer on top. Siless has two recommended options: a 157 mil closed cell PE foam, or a 200 mil 3-layer hybrid - 50 mil butyl mastic, 100 mil closed cell PE foam, and 50 mil mass-loaded membrane. I’m on the fence here. I would think the 157 mil PE foam gives better heat insulation while the hybrid gives better sound insulation.

Any thoughts on one vs the other for a second layer?

I think I'd lean toward the 200mil hybrid, but I haven't used these products, so take my lean with a grain of salt. @Moab is the king on this topic and I think I'd look at that Facebook group just mentioned a few posts up.

I will say that I laid down some Noico on the sides of the transmission tunnel and behind the HVAC back in February. In late October I added 1/4" rubber in all four footwells and the rear tub area and it made an obvious difference. It is amazing how much nicer it is to drive with vibration dampened. I'm also going to add some 1/4" rubber on the driver's side firewall. I'll probably call it quits at that point. I would consider what I did mild and I can easily remove the rubber mats if I needed to for any water ingress.

 

[Moab]

Actually @Chris is the king. He covered the tub on his old TJ with sound deadener and thick rubber mat. In a very professional way. He has pics somewhere. It was the nicest job I've ever seen. I used his advice and researched this alot. I just took more pics and wrote about it during the installation.

But I think 157mil or 200mil is way overkill. Your not blocking noise so much as your stopping noise from vibration in the tub steel. Single panels in major areas can do that. And if you want to block noise - not so much "deaden" the vibrations - I would use that thick rubber mat. I forget the technical name. But Noico sold it. It's like .5" thick foam rubber of sorts. But I assume it's heavy too.

200mil weight alone is going to add up fast. You don't realize how heavy this stuff is until you pick up a box. A 6 inch thick box of this is heavy as hell. Like hard to pick up. You add this a couple steel bumpers and rock sliders. And your going to slow down and need to start second guessing a lift or other additional weight. This why everyone puts bigger motors in. And why alot of guys run stock.

They spent millions engineering the TJ. For a perfect match of weight and power. Not to much and not to little. But the aftermarket options are many. Second battery, bumpers, sliders, onboard air, extra gas, gear. It adds up quick. And the 4.0 tractor engine, while being massively reliable and rugged, is not a major powerhouse. But it was engineered that way.

My advice? No harm in starting with less. See what you get. Then add more if you need too.

I was going doing the same thing. Trying to kill as much noise as possible. I ended up with Caddilac thick plush carpet. And a thick layer of sound deadening and heat shield. It was a bit overkill for a Jeep to be honest. And with a soft top your only going to get so far.

Just consider your entire build first. Figure out a max weight that the TJ can handle above stock. Then add up everything you want to do first. Then decide if that extra 100lbs of sound deadening is worth swapping for your extra battery or sliders or whatever. Or at least start with single panels of 60mil.

It's like backpacking. You don't buy a pack first. Because you'll fill it with bs and it will quickly become to heavy. And you'll be slow and weak. Just like your Jeep.

Figure out what you "need" to take first. Then buy a backpack just large enough to fit it all. Or a Jeep that isn't going to be strapped with to much weight.

You add all this sh*t. And then at some point you realize your Jeep is to heavy. And power is suffering. And just like a backpack you have to much sh*t. And already missing items that are essential to your build.

Make a spreadsheet of weights. Ask @Chris or some of the OG members what that weight limit is. Or a range. And plan accordingly. Don't buy shit first. And start adding it. You can't return sound deadener once it's applied. And honestly you can't remove it. It's a major bitch. Like I wouldn't even try.

Read and research hotrods. Those guys use sound deadener way more. And their goals are way more silent. They know what works. Same with audio guys.

 

[Tob]

Actually @Chris is the king. He covered the tub on his old TJ with sound deadener and thick rubber mat. In a very professional way. He has pics somewhere. It was the nicest job I've ever seen. I used his advice and researched this alot. I just took more pics and wrote about it during the installation.

But I think 157mil or 200mil is way overkill. Your not blocking noise so much as your stopping noise from vibration in the tub steel. Single panels in major areas can do that. And if you want to block noise - not so much "deaden" the vibrations - I would use that thick rubber mat. I forget the technical name. But Noico sold it. It's like .5" thick foam rubber of sorts. But I assume it's heavy too.

200mil weight alone is going to add up fast. You don't realize how heavy this stuff is until you pick up a box. A 6 inch thick box of this is heavy as hell. Like hard to pick up. You add this a couple steel bumpers and rock sliders. And your going to slow down and need to start second guessing a lift or other additional weight. This why everyone puts bigger motors in. And why alot of guys run stock.

They spent millions engineering the TJ. For a perfect match of weight and power. Not to much and not to little. But the aftermarket options are many. Second battery, bumpers, sliders, onboard air, extra gas, gear. It adds up quick. And the 4.0 tractor engine, while being massively reliable and rugged, is not a major powerhouse. But it was engineered that way.

My advice? No harm in starting with less. See what you get. Then add more if you need too.

I was going doing the same thing. Trying to kill as much noise as possible. I ended up with Caddilac thick plush carpet. And a thick layer of sound deadening and heat shield. It was a bit overkill for a Jeep to be honest. And with a soft top your only going to get so far.

Just consider your entire build first. Figure out a max weight that the TJ can handle above stock. Then add up everything you want to do first. Then decide if that extra 100lbs of sound deadening is worth swapping for your extra battery or sliders or whatever. Or at least start with single panels of 60mil.

It's like backpacking. You don't buy a pack first. Because you'll fill it with bs and it will quickly become to heavy. And you'll be slow and weak. Just like your Jeep.

Figure out what you "need" to take first. Then buy a backpack just large enough to fit it all. Or a Jeep that isn't going to be strapped with to much weight.

You add all this sh*t. And then at some point you realize your Jeep is to heavy. And power is suffering. And just like a backpack you have to much sh*t. And already missing items that are essential to your build.

Make a spreadsheet of weights. Ask @Chris or some of the OG members what that weight limit is. Or a range. And plan accordingly. Don't buy shit first. And start adding it. You can't return sound deadener once it's applied. And honestly you can't remove it. It's a major bitch. Like I wouldn't even try.

Read and research hotrods. Those guys use sound deadener way more. And their goals are way more silent. They know what works. Same with audio guys.

Fair points. I do stay conscious of added weight, but I am willing to compromise to combat NVH. I live far from good wheeling and won’t invest in a truck and trailer just for Jeep hauling. Thus I have to make the TJ as quiet and smooth as can be to make roadtrips less loathsome for my wife (and myself, but I am far more eager than her to suffer through it to get where we’re going).

That being said, I will go with the 80 mil CLD and 157 mil PE foam for its lighter weight.

 

[Kiwi TJ]

I use my Jeep for mainly overlanding so lots of longer drives (4-10 hours ) I went with the Noico stuff and used it in my tub (up the firewall and wheel wells etc) big reduction in road noise although having a soft top there is not much you can do but the stuff does make it quieter...even with my older soft top. I put Bedrug on top.
I will add a good choice of tire will also help with noise reduction so don't over look that.

 

[StimpsonJCatt]

After reading all 20 pages of this thread a couple of times, I was like, I gotta do this too so I found some Noico on Ebay and went at it. After now finishing, I can't say I ever want to do it again but then decided to torture myself a little more and added OEM grade 3M Thinsulate (I had leftover from previous build that never happened) sound absorbing layer on top. It was A LOT of hours and I hope I will be able to tell a difference....

 

[Mercury]

After reading all 20 pages of this thread a couple of times, I was like, I gotta do this too so I found some Noico on Ebay and went at it. After now finishing, I can't say I ever want to do it again but then decided to torture myself a little more and added OEM grade 3M Thinsulate (I had leftover from previous build that never happened) sound absorbing layer on top. It was A LOT of hours and I hope I will be able to tell a difference....

View attachment 592728

Let us know how it works! This is one of the last steps for my build and I'm curious how well it combats road noise and improves bass.

If you have a hard top did you cover it as well?

 

[StimpsonJCatt]

Let us know how it works! This is one of the last steps for my build and I'm curious how well it combats road noise and improves bass.

If you have a hard top did you cover it as well?

Will do. haven't driven it yet as I am still in project mode but sitting in it in the garage and just shutting the door I can tell a difference. No hard top.

 

[Kiwi TJ]

MOAB - just planning my trip to the states in May… and wondering who will be in Moab in the last two weeks of May?
@Apparition i think you mentioned you’re going ??

 

[Apparition]

MOAB - just planning my trip to the states in May… and wondering who will be in Moab in the last two weeks of May?
@Apparition i think you mentioned you’re going ??

Unfortunately we’ll be there the first full week of May.

https://wranglertjforum.com/threads/moab-in-may-2025.82151/

 

[Kiwi TJ]

Unfortunately we’ll be there the first full week of May.

https://wranglertjforum.com/threads/moab-in-may-2025.82151/

Thanks I’ll jump on that link