Opinions wanted on a quieter ride.

Warning....long post ahead.

Every June I drive up to Canada's beautiful Lac Seul to catch post ice-out walleyes and my 93 XJ Sport has always been a trustworthy way to make the fourteen hour journey. Now, my dad, after several health issues and what-not isn't the same man he used to be and my brothers and I want to make the drive as comfortable as possible for him and I'm looking for sound dampening suggestions. It may sound corny but it'd be worth a lot to me to get some advice on the subject. Keep in mind too that there is no way I'm going to get a different vehicle. The XJ stays. It's almost as much a part of the trip as the people involved.

First thing I did was replace the entire Fred Flintsone floor pan, herculiner it, and cover it with hushmat. (after I replaced the leaky windshield, of course) Then I did the doors...BIG difference.

I feel like I've wasted my money, though. From what I've read a lot of these expensive sound deadening measures could have been acheived by using really cheap, asphalt based undercoating spray. I'm at a point where I'm reworking the headliner and I'm to the point where I either spend fifty bucks for dynamat/hushmat type sh*t or I spend seven bucks on a can of 3M undercoating. Any experience in this matter out there? Anybody else have some inventive sound deadening measures? (besides replace the cracked manifold, of course! :laugh::laugh: Thanks!

the biggest thing u can don is put in carpet and the padding back in the floor over top of the hushmat. that makes a huge difference ov er the bedliner. ypu can also try putting the hush mat inside the rest of the inner body panels instead instead of just the door panels. wat about ypur tires and exhaust?

what about your tires and exhaust?

Tires are regular Goodyear wranglers with about 15K worth of tread left on them. I'd really like to get some Bridgestone Revo's but the tread design looks like it'd be noisey. Exhaust? Stock. Has been cat-back upgraded in the past but the supposed gains weren't much to care about. Good call on the under-padding. Right now I've got zero because it's one less thing to soak up water and mud.

here's what i did...a really thick headliner..

http://www.naxja.org/forum/showthread.php?t=903256

I went from the Wrangler RTS tires to the Revos and didn't notice a sound difference. very very good AT tires.

x2 I have bridgstone A/T on the wifes jeep, no extra noise.

No kidding? Well...guess what tires I'm buying soon!

Anybody ever do anything to make the backseat more comfortable? I think I remember seeing somewhere how somebody added rear-headrests to their XJ. I've searched hi and low but I can't find the link I was thinking about. That or I could just tell my brothers to deal with the long Minneapolis to International Falls drive with a Bud or two.

Thanks, Silent Bob!

Pet subject here.

First off those expensive sound deadners, the rubber ones generally speaking are best for deadening AND not falling off in the middle of a hot summer. Asphalt especially cheap Home Depot "peel and stick" can soften with enough heat and fall. It's all effective and difference between the most expensive stuff versus the least expensive will really only "show" with a decibel meter. But the inexpensive stuff is still pretty spendy. The reason for this being that they are all of comparable weight, thickness and elastic quality.

I'm going a different route, I've got some recycled rubber mats 1/2 inch thick, made out of granular rubber (ground up tires). They are made for all sorts of applications from Horse stall mats to Floor tiles (noise and anti foot fatigue) they even make them in Plywood sheet sizes (4'x8') I've got a 4x6 sheet in the back of my Cherokee right now and another 4x8 one that I will cut for hollow areas.

I'll be using adhesive (probably Liquid Nails) to permanently attach sections as I cut them to fit into every hollow interior space. Even though it's thick it's still very pliable and will conform to outer sheet metal in places like the rear quarters or inside the door skins.

It will add MORE mass than those expensive Butyl rubber or Asphalt sound mats, it will block more sound acoustically (they all block sound by adding both "acoustic mass" and by stiffening the panel they adhere to so that it doesn't vibrate as much. This stuff will do both of those better (especially if they are adhered to the metal with hardened urethane glue) and it can be had for a couple dollars a square foot. I paid 30 bucks two 4x8 sections 1/2 inch thick (from a general contractor I know who had a few left from a job). I seem to recall Dynamat costing like 24 or 30 dollars a square foot IIRC. So it's heavier, cheaper and much better at eliminating elastic resonance in body panels (floppy vibrating sheet metal).

After that I'll use expanding waterproof urethane foam inside the A, B and C pillars and the channel above the doors that runs around the roof.

Finally for the head liner I'm thinking Industrial felt... the kind of stuff they use as vibration dampeners under industrial machines. I don't know if I want more than two sheets worth of the rubber, for weight reasons (each mat is like 35 at a guesstimate) And I want something softer up their near my noggin anyway.

There are definitely alternatives out their if you get creative.

So where is a source for those rubber mats you are talking about. I am thinking they are something like those ones that can be snapped together like a puzzle piece that I've seen some places but they were expensive in those 2x2 sections.

Have you changed springs shocks or C arms? Stiffer springs and shocks will transmit a lot more noise inside. Some lifted Jeeps tend to be a bit noisier too (IMO) . C-arms that replace the rubber bushings with almost anything else tend to transmit more noise inside.
I take my dad fishing and his legs are bad. It is nice to back the XJ right into the water. He can fish all day from the hatch..

I replaced my headliner recently and added some of that "bubble wrap" foil lined insulation between the roof and the head liner. It worked well for insulation. Seemed to cover up some sound and was light enough to not cause any probs with the headliner itself.

I do agree with the bushing idea however as most of the sound is coming from the interface between road and the frame. Any tire with decent meat on it is going to make some noise.

And I like the idea about the foam in the body cavities.

ParadiseXJ said:

I replaced my headliner recently and added some of that "bubble wrap" foil lined insulation between the roof and the head liner. It worked well for insulation. Seemed to cover up some sound and was light enough to not cause any probs with the headliner itself.

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i did this in my floor pans also.

I wonder how it would work if I took a few of the lawn bags full of foam shipping peanuts I've collected over the last few months and dumped them in the rear quarter panel cavities.

Awsome thread.

How are your door and window seals? The door seals are realitivly cheap and easy to replace.

For comfort, I have seen an XJ that had all leather seats, and dash from a ZJ.

RichP said:

I wonder how it would work if I took a few of the lawn bags full of foam shipping peanuts I've collected over the last few months and dumped them in the rear quarter panel cavities.

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Foam packing peanuts are cellulose i think and definitely water soluble (for biodegradability might be a puddle of gunk in their after a few months:scared:

as far as a source for the mats I dunno I got mine from a contractor they are still a little "specialty" but they should be available all over the net from various manufacturers. I would start searching for "recycled rubber flooring"

Another really good option and super cheap at like 30 bucks, ALSO from the construction industry is a box/Sprayer (all in one) of Urethane expanding foam, like they spray inside of walls of houses.

That stuff is pretty easy to deal with (just don't get it on anything you don't want to have foam on, including yourself!) they usually come with a gallon or more with a sprayer attached because they are one shot deals (after use there's no cleaning them).

With that you could put on an even 1 or 2 inch coating of foam on every panel. This wouldn't add that much mass but probably as much as thin butyl rubber sound deadener mats do. but it would utterly KILL elastic resonance, like putting a pillow on a guitar string.

KSXJ said:

For comfort, I have seen an XJ that had all leather seats, and dash from a ZJ.

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I'm doing this too, in fact I just picked up a set of fully powered Ford Taurus SHO leather seats off Ebay, SHO's came with deep side and leg bolsters and even shoulder bolsters (like a leather racing seat) I've always been partial to Ford Leather seats, my Mustang GT and Cobra both had great seats.

Got them for 99 cents.... Got to love local pickup auctions with no reserve. They are in insanely good shape the owner was seriously into his SHO.

Probably do a write up here once I've fab'ed the brackets to mount these, I've test fitted them already and some brackets are a must.