M35A2 Sound Deadening Project

Hello all, first off, I'm a very new M35A2 owner and I would like to thank everyone for the tech info posted up on this site. With a few hours of searching, I was able to answer most of my own questions; thanks for sharing all the knowledge.

My question is this: Has anyone attempted to deaden out some of the in-cab noise in their Deuce? I know, I know, don't get me wrong, I love the sound of it but I'm going to be making some very long hauls (8+) hours with my 4WD trail rig stapped down on the bed and I'm looking to make it a bit more comfortable.

Has anyone tried the product FatMat? The reviews of it online look promising and the price is about half of what Dynamat wants. Any other products or homebrew jobs out there that did the trick?

I'm going to be adding a muffler to the truck shortly and ideally when I'm done with the soundproofing my goal is to not have to wear hearing protection while operating the vehicle. No, I'm not looking for noise levels that one finds in a Cadillac or Lexus. Any suggestions appreciated, Ross

Run the exhaust underneeth and steel sound deadner from wrecker powerstroke trucks or dodge diesels. Look under the carpet of some diesel trucks. I have not tried this yet but its a good hunch.
Met a veteran the other dat and he said he used normal house insulation stuffed up in the firewall and dash areas.

Welcome to the site CurryRA. Here's one example of someone on a mission to deaden sound. You will be reading for a bit but trust me, it's in there!
http://www.steelsoldiers.com/showthread.php?t=4696

Thanks for the quick replies. I'm still churing through the attached link but it is excellent! Thanks.

Just to be sure...there's no problems with re-routing the exhaust back the rear of the truck? I'm not very up on diesels/turbo's (I'm working on it) but the turbo performance won't be affected by longer pipes/slightly higher backpressure will it?

I know alot of guys, buy the closed cell foam sleeping mats from GL and glue that down. It works well and is cheap.

The best way to deaden the sound is to never hit the red button by the steering column.

It won't matter that much to you in the PNW, but those of us in the South have to deal with extreme heat as much as noise. Mike who wrote the thread and built the truck in the link above had a few comments at the 2007 GA Rally about his insulation. He said the noise and heat were reduced a lot. But, over a long drive or starting with a hot truck, the heat got more and more. It was trapped inside the cab.

I am not trying to speak for him. Just passing on a side effect of sound deadening. These trucks make a lot of heat running down the road. The cab will become heat soaked after a while.

CurryRA,

My brother used the FATMAT Product in his 1972 Morris Minor Mini-Cooper. He said that stuff is really sticky and works very well. Considering the price difference between the FatMat and DynaMat, he said it was well worth it.

Just thought that I'd let you know,

Tyler

I drove my M109A2 shop van across the US on US Rt. 20 this summer, July 31 to August 28. I installed the artic winterization insulation kit in the cab(similar to fat mat), installed a muffler #24216, and lengthened my exhaust stack 13 inches. My rider and I were able to talk to eachother for the 7000 mile trip. No hearing protection required. Wish I had it during a few of his conversations!!!!! The muffler came from a local speed shop, called a Dynomax 24-216. Fits the 3.5 inch turbo exhaust stack, cost $60 delivered to me. straight thru design, no loss of power. The big trick is to lengthen the stack as much as you are willing to. Or, take it out horizontal to the right side tandems where it used to be. That would work even better. JT out

Really appreciate all the replies here. Where I'm at in the PNW it rarely gets above 85 degrees on a blistering summer day so the heat retention problem shouldn't be nearly as much as a problem as other parts of the country.

At this point I think I'm going to try some of the FatMat stuff combined with muffled exhaust and perhaps some of the old sleeping pads from GL Thanks for all the info again.

I love the noise level....HUH??? HUH???

I love the noise too. At least I did till I drove mine for 27 hours straight. My ears hurt from the ear muffs and ear plugs.

But its an easy fix. I'm just going to have to buy another one. Put some sound proofing in one, and annoy the neighbor with the other one.

Nice Sounds like a plan....

I have an exhaust diverter I got out of an M49 tanker from Cranetruck, and am planning to run the normal stack, and then run a pipe to the rear tandums, so on long trips, I can pull a cable and the exhaust is routed out the back, and on short trips or parades and the like I can run it up the stack. Just need a few more peices of exhaust pipe and I'll be done.

That reminds me, any of you guys get a rusted out J pipe, could you cut the ends off and send them to me? I've already welding one onto the box, so I can just reuse the clamps, and everything can be taken apart easy if I want.

Ferroequinologist said:

I have an exhaust diverter I got out of an M49 tanker from Cranetruck, and am planning to run the normal stack, and then run a pipe to the rear tandums, so on long trips, I can pull a cable and the exhaust is routed out the back, and on short trips or parades and the like I can run it up the stack. Just need a few more peices of exhaust pipe and I'll be done.

That reminds me, any of you guys get a rusted out J pipe, could you cut the ends off and send them to me? I've already welding one onto the box, so I can just reuse the clamps, and everything can be taken apart easy if I want.

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That's a pretty smart idea. The ole man and his friends did a similar thing with a cut out hole in their exhaust pipes pre-muffler and some wing nuts, on their Buicks and things back around 1958. Good way to be able to choose whether you hear the "music" or not!

mine are not loud enough what did you say sonnny darn hearin aid

jatonka said:

I drove my M109A2 shop van across the US on US Rt. 20 this summer, July 31 to August 28. I installed the artic winterization insulation kit in the cab(similar to fat mat)

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I too have this insulation but have yet to install it. how did you attach it to the cab? what glue did you use? what prep did you give the metal?

jatonka said:

I drove my M109A2 shop van across the US on US Rt. 20 this summer, July 31 to August 28. I installed the artic winterization insulation kit in the cab(similar to fat mat), installed a muffler #24216, and lengthened my exhaust stack 13 inches. My rider and I were able to talk to eachother for the 7000 mile trip. No hearing protection required. Wish I had it during a few of his conversations!!!!! The muffler came from a local speed shop, called a Dynomax 24-216. Fits the 3.5 inch turbo exhaust stack, cost $60 delivered to me. straight thru design, no loss of power. The big trick is to lengthen the stack as much as you are willing to. Or, take it out horizontal to the right side tandems where it used to be. That would work even better. JT out

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how does that muffler sound, I've heard the napa muffler and I couldnt stand the sound at all. a video would be great if you can.