The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Soundproofing

After four years in the making and more money than I care to think about, I'm pretty happy with the restoration of my 66' C10 Shortbox except for one thing, the road noise!!! I know some of it's my own fault (two quite loud glass-pack mufflers). But what can I say? I'm a child of the 50's when dual exhaust and a pair of roaring Smittys were all the rage!!! But still, trying to listen to my stereo system at anything over 40 mph is pretty much a lost cause.

The new carpet was installed using some sound proofing pads from LMC as well as the usual felt carpet pad. The entire floor is covered and up to the rear window behind the seat. (The gas tank has been removed and placed between the frame rails under the bed.) Since, I have purchased enough Dynamat Xtreme sound proofing to do the doors and the floor. So far I have covered the kick panels (leaving the vents open) and the back side of the removable door panels. The holes in the actual door are too small to do much inside the doors.

I plan to take the seat out, take up the carpet and pad, remove the heater box and firewall pad, and cover the entire surface with the Dynamat sound proofing.

But you know, I was born in 1939 (do the math) and I'm starting to wonder if it's going to be worth all that work. My back aches just thinking about it!!! Doing the kick panels and the removable door panels hasn't produced any results that I have noticed. Maybe I should just purchase a pair of cheap ear plugs and be happy. Any input on this matter would be appreciated.

You probably have it as quite as its going to be. Most noise over 40-50 mpg is wind noise. These trucks were not made to be quite.
I know what you mean about the 50,s. I was born in 34 & it is tough working on these trucks anymore.
George

Thanks for the reply, George. Hope we don't run out of Tylenol before I get my truck finished!!!

Larry

Larry,

Have you done the rubber in the door jambs? How about all the window seals? You didn't say in your post above.
Adjusting the doors so that they close firmly and seal up is about the only other thing that can be done.
Like Wrench said, they are not quiet trucks.
I did all the same sound deadening that you have done, and the difference is amazing over what it was when I first got this truck, but it is not as quiet as my '06 Dodge.

Dave

Thank you for the input on soundproofing my 66'. Not sure what you meant by "the rubber in the door jambs". In the restoration process all new door weatherstrips and window channels were installed. I particularly liked the "no glue" door weatherstrips. At highway speed I do not detect any cold air coming in except a little through the kick panel vents because they don't seal up 100%. When I installed the Dynamat soundproofing on the kick panels, I didn't what to cover up the vents as I don't have air-conditioning. So I guess I'll just have to live with that.

I think I agree with George (Wrenchbender Ret.), most of the noise at highway speed is just wind noise. It's just the way they were made!!!

...where does your dual exhaust exit the truck. I once had the problem on a late model. If the exhaust pipes are turned to the outside, behind the wheel, you may be getting some exhaust noise from your type of mufflers?
..just a thought.

Rubber in the door jambs was referring to the weatherstrips you replaced. Sounds like you got the doors adjusted well if you have no cold air coming in. Those vents will never seal up completely, it's the way they were designed. Sounds like you have done about as much as you can. These trucks were never meant to be luxury car quiet. Most of the time they were just old farm trucks and never saw much over 40mph, not much noise at that speed. they can do more with no problem, they just get noisy.

I think Achipmunk may be on to something there with his exhaust question. I had Glasspacks on my old '63 longbed, but the pipes went all the way back. I built that one in the '70's. I built my '62 in this century. It is a shortbed with the pipes turned out just behind the cab, under the side step. Thankfully. I don't have glasspacks any more. I went with Flowmasters this time around.

I'm thinking about skipping all the soundproofing products and going for an aviation style solution:

https://www.sportys.com/pilotshop/david-clark-h10-13s-headset-stereo.html

Wire some stereo jacks & a push to talk switch under the dash. Could be pretty cool!?

One of the big mistakes that most builders of pickups do is to put the mufflers under the cab and exhaust pipes exiting near the rear wheels.
I generally have the mufflers on a pickup, regardless of what kind of mufflers they are, placed as far under the bed, away from the passenger area, with the pipes extending out under the rear bumper.
The mufflers on my '64 are chambered stock type with 2-1/4" pipes running all the way to the bumper. The inside of my '64 is very quiet, I used a lot of Danamat and/or Road-Kil on the floors etc. I also added weatherstrip rubber on the upper edge of the door where it meets the A pillar.. The Delux C series AC equipped camper specials came with this added door seal.
Of course when the truck gets above 65 mph the wind noise really picks up.
I generally drive my '64 with the windows up and the AC on, makes a big difference in the wind noise.

Thanks for your reply, Wm L. I removed the seat, heater box, fuse panel, firewall pad, carpet and carpet pad. Then I cleaned up all the glue from the last carpet installer and have just finished covering everything with Dynamat Extreme including the kick panels and firewall up as far as possible. I have also covered the back side of the removable door panels with Dynamat. I would like to put some of the Dyanmat inside the doors as well but the access holes are pretty small to do that.

But I am not familiar with what you called Road-Kil. Is that a specific brand of sound- deadner or just a generic term?

I like your idea of moving the mufflers back from under the cab as far as possible. My exhaust pipes do come straight out the back. Is the Camper Special weatherstrip you mentioned available someplace?

Thank you.

Larry, Road-Kil is a product very similar to Danamat, my upholster turned me on to the product. It can be purchased on ebay by the box, make sure you purchase a good plastic roller from the vendor, the plastic roller holds up much better than the wooden one.
The camper special "door to A pillar" rubber is very hard to find, the vendors looked at me like I was crazy. The F series 78-79 XL Broncos had the same door trim. I have a 98 Jeep Cherokee Sport that also has a similar weather seal on the upper leading edge of the door.
I have taken the vent windows out of my doors, have power windows and power door locks. Getting rid of the vent windows reduced the wind noise and improved the visibility. I have upholstery on my doors, kick panels and head liner. wm.

Thanks so much, Wm L, I'll look into it. Do you like the Road-Kil better than Dynamat?

Thanks for the tip Orr3R. Actually, the last time I was at our Indoor shooting range I purchased ear protectors that I can plug my MP3 player into. If all else fails....

Larry, I think that Road-Kil and Danamat are pretty close to being the same product. The Road-Kil I have purchased, have done three vehicles with it, is as I recall, 16" x 32". As I understand Road-Kil is used extensively in the sound recording/music industry. Many of the "car guys" I know are "thrifty to a fault" they like to use insulation designed for heat/AC ducts in lieu of products that are intended to limit sound transmission.
The fact of the matter is that vintage trucks, meaning pre '70 were intended to be work/utility trucks, not luxury cruisers.
I have a 2019 Silverado that is the nicest truck I've ever had, up-grade from a 2001. My truck is so smooth/quiet, before you know it you are going 80 mph, of course it weighs over 6k. Wm.

Footnote;
Just went online, 'eBay' looking for Road-Kil.. It appears the product is no longer available, however, there is a product called Kil-Mat which appears to be very similar to Danamat, comes in sheets, boxes. wm.

I did a little more research on Road-Kil yesterday.. I keyed the name in wrong is why the product did not come up, the actual name is STINGER- RoadKil.. They have an extensive sound control/deadener line, hood, trunk pads, insulators for speakers, etc. The sound control mats come in several sizes, the best buy being the 18"x 32, 36 sqft per carton. The price varies from vendor to vendo, a low of $104. up to $128. The $104/128. is for the RoadKil Expert which is .080 mil.
I ordered a carton of 36 sq ft, 18 x 32 'Expert', $104. free shipping. Wm.

An interesting side-bar to soundproofing a vehicle is the evaluation of vehicles. By the mid thirties open cars were quickly becoming a thing of the past, very few roadsters, if any, having been replaced by enclosed coupes, sedans. About the last roadster pickup built in the States was in '32.
By the late '30's noise and comfort was quickly becoming a big issue. I read an article many years ago that pertained to the gear shift lever. The lever protruding through the floor was very difficult to restrict air flow, however, the big issue was noise. The gear shift stick transmitted the majority of the power-train noise into the passenger compartment.
A second problem with a floor shift was, it was a common believe by men that women could not use their feet and hands at the same time, therefore, it was very difficult for a woman/female to drive., Ya know, pat your head and rub your tummy at the same time.
1939 saw the majority of cars with column shift available and/or standard on Deluxe vehicles.
I have several auto brochures from 1939 that show a woman in the drivers seat with her gloved right hand on the column gear shift.

Your comment about the floor shift transmitting a lot of noise made me share this tidbit. My modern truck (a F##d Diesel) has a floor shift, and when I had to get the transmission replaced, the dealership didn't get the boot screwed down to the floor. It sounded like the engine was in the passenger seat. The boot isn't just a thin rubber thing, but there's also another boot beneath it made of thick rubber (maybe 1/8-1/4" thick). So some of you guys with floor shifts might think about stuffing the shift boot with something (the heavier the better).

I want to thank all who have offered suggestions and comment on my 66' Chevy soundproofing project. I just finished it today (5/1/2020). As I mentioned before, I pretty much stripped the interior then started back with a layer of Dyamat, then a layer of jute soundproofing w/aluminum backing and then a new molded carpet from Brothers. I covered the entire floor and up the entire height of the firewall. (That was fun!!!) Also installed a new rubber firewall pad.

And speaking of the rubber firewall pads, wouldn't be nice if they could make them to fit? The passenger side was fine. The driver's side was joke. And how many of the rubber firewall plugs have you ruined? I found a secret. I ground off the point of an old Phillips Head screwdriver to push them in with and put a dab of some really soft wheel bearing grease on the tips of the plugs. It wasn't foolproof but with a sharp rap they usually popped right into place. Also use a screw driver slightly smaller than the hole in the plug. If it's the same size, the plug will not go into the hole.

It was a job!! But the worst part was finding all the little screw and bolt holes under all that soundproofing. Like the two small screws that hold the fuse panel to the firewall. I think I spent over an hour just getting the gas pedal bolted down!! And getting all 8 seat bolts just right was also a project. I know I could have cut bigger holes for the bolts but I get way to fussy for that.

Anyhow, this afternoon was the moment of truth. Yes, the cab was much quieter now but not as much as I had hoped for. And now the road noise is diminished, the wind noise is more noticeable!! But I hate to admit defeat, I still love my truck. I think Wrenchbender Ret. had it right weeks ago when he said these trucks were not built to be quiet. So turn up the radio and live with it - right!!!!

REUP

Right

Did you locate weather stripping for the door to "A" pillar... It will extend from the upper door hinge to midway over the vent window. attaches to the door, not the jamb. The upper seal on a Jeep Cherokee attaches to the 'A' pillar. The upper door seal on a '79 Ford XLT Bronco is very similar to the C-10-20 attaching to the door.
The transition from 'work-horse truck' to 'cow-boy Cadillac', evolved very slowly. Wm.

Hi again, Wm L. Several months ago we corresponded about weather stripping for the door to "A" pillar on my '66 C10. I apologize for not getting back to you until now. Just had a lot of other projects that took preference. I believe they call them "Honey Do's".

So, I would like to find these weather seals. Would they be listed as 1964-66 C10 Camper Special Door Weather Seals? Any suggestion where to look?

Thank you "W". I finally got a 700R4 installed in my truck replacing the old PowerGlide. Wow, what a difference!!!

Reup