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Sound deadener

Discussion in 'The Hokey Ass Message Board' started by wide34, Jul 28, 2011.

  1. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    I've installed Lobocrud's insulation in my cab walls, roof, doors, and firewall and hushmat on the floor. It is reasonable quiet (I can hear someone talk) until I get t0 65-70 MPH, then I get a loud howl (can't hear anyrhing) that sounds like it is coming from air being trapped under the windshield visor. Anyone have this problem and how did you fix it. I've seen the visor louvered and/or drilled and I assume that helps but I don't want to do that. Appreciate any ideas.
     
  2. Joe Johnston
    Joined: Jun 29, 2008
    Posts: 127

    Joe Johnston
    Member
    from Ohio

    First remove the visor and drive to make sure that is the cause. It could be something else.
     
  3. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,426

    Von Rigg Fink
    Member
    from Garage

    might be your front window seals?
     
  4. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    I should have mentioed that this is a 34 ford pick-up so the visor isn't removeable. Thanks for the suggestion.
     

  5. Tin Can
    Joined: Nov 18, 2005
    Posts: 2,096

    Tin Can
    Member

    tape off the bottom of the visor since it isnt removable and see if the noise is still there. Just an idea
     
  6. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas


    The winshield is glued in and I can't feel any air around it but I'm going to check again, I'd really like to find out what it is because I can't go 60!
     

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  7. roundvalley
    Joined: Apr 10, 2005
    Posts: 1,774

    roundvalley
    Member

    Get some duct tape and cardboard and do a temp. block on the visor.
     
  8. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks for the idea, I'm going to give it a try this week-end.
    Any suggestions on how to keep it from blowing off, I don't want to use a tape that will pull the paint off.
     
  9. Hackerbilt
    Joined: Aug 13, 2001
    Posts: 6,251

    Hackerbilt
    Member

    Try one of those venturi air blowers for drying water-borne paint.
    You can buy them cheap at our Princess auto...so I suspect you can get them at Harbour Freight as well.
    I've found them to work good to find air leaks and noises without having to actually roadtest continuously.
    You sit inside and a friend can slowly move the air flow around until the location of the noise is identified.
    Doesn't always work of course...but it works often enough to be worth a try.
     
  10. Stevie Nash
    Joined: Oct 24, 2007
    Posts: 2,999

    Stevie Nash
    Member

    Nice lookin' ride by the way!
     
  11. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks Bill, I'm reasonably certain this isn't an air leak but rather a vibration caused by air trapped under the visor (of course I can't prove it but thought someone else migh have had the same problem). I've been thinking about either adding hush mat material to the roof or even replacing the lobocrud material with hush mat but was hoping someone else had the same problem. I don't think widening the body would have made any difference to the noise level but obviously I could be wrong!
     
  12. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks, I'm really having fun with it but just can't hear anyone!
     
  13. If the visor is vibrating, and not producing some kind of turbulence, it might, might mind you, help if you added small weights. Then again, it might make the situation worse. It is also possible you have some kind of harmonic thing going on, in that case the problem would solve itself if you went fast enough. Adding weights in the appropriate place would alter the harmonics, hopefully solving the problem. Another possible fix, assuming it is a harmonic problem, would be to change the airflow in some matter. Yet another possibility would be to make the visor more rigid.
     
  14. alchemy
    Joined: Sep 27, 2002
    Posts: 17,280

    alchemy
    ALLIANCE MEMBER

    Early '32 pickups had no brace on the visor underside, and that was quickly changed. I'm guessing Henry found a problem (vibration?) that needed fixing. Did you remove the underside brace on yours when you widened your cab?
     
  15. Having lived with a '32 Ford Pickup I know what you are talking about but seriously,,they also happen to have the aerodynamics of a barn so I can't be convinced there is any way to quieten all the buffeting of air around and under the visor.

    Having known someone in the past that had a model A sedan with louvered visor all it did was create a whistling noise that was worse than the wind noise! HRP
     
  16. oldolds
    Joined: Oct 18, 2010
    Posts: 3,189

    oldolds
    Member

    Take the front bumper off. My OT work van has a cargo rack on the roof, it is made of pipe. Over 60 mph the whistle can get quite loud. I have had this rack on a few different vehicles, the sound changes with vehice and where it is positioned on the vehicle. Even those single pipe ladder racks can make a lot of noise inside the vehicle.
     
  17. 3banjos
    Joined: May 24, 2008
    Posts: 478

    3banjos
    Member
    from NZ

    Cool, could be in your favour. I'd go 65-70 with the missus beside me..:)
     
  18. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks for the idea, as you said I think I've got some sort of harmonic thing going on. I can get some fairly heavy magnets and attach them to the undersdie of the visor to see if that makes any difference. Will let you know.
     
  19. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks for the suggestion. I split the cab in the center and widened it 8 inches and added braces on either side of the new filler piece. However the visor could still be vibrating, I can't notice it when I'm driving but it may be a small vibration. I'm hoping the magnets might help.
     
  20. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Thanks for letting me know I'm not the only one this has happened to, have you tried any of the sound deadeners to quiet the noise?
     
  21. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas


    Love it- someone else suggested getting hearing aids!
     
  22. No, it's a hot rod and everything I own is noisy,:D HRP
     
  23. wide34
    Joined: Mar 2, 2006
    Posts: 536

    wide34
    Member
    from Texas

    Had time this week-end to try several suggestions, took 6 1/2 lb. magnets and fastened them to the underside of the visor and it seemed to make some difference but not enough to be able to hear anything. Also took an aluminum bar and fastened it with PS tape to the visor to try and stop any vibrations but that again seemed to help a little but still not enough to hear anything. I looked at trying to block air from getting under the visor and really couldn't come up with a practical way to do it so abandoned that idea. Sunday Morning I stopped by the local bakery/car show and got to talking with another 34 ford pick-up owner and he immediately knew what I was talking about and took me for a quick ride in his pick-up. At 80 we could still talk (I don't want to imply this was a "limo" ride as there still is plenty of noise, just not the shrill howl I was getting). We then went for a ride in mine and after pulling the plugs from his ears he pointed out that I didn't have any insulation in the header above the window (I have my windshield wipers up there and not a lot of room) and he felt that might be where the vibration was coming from. He had used Second skin damplifier in his truck and still had a couple of pieces left which he offered to me (there really are still some great people in this hobby) which I gladly accepted and he helped me put them in. The ride now is at least tolerable even with just a couple of pieces installed. I've ordered some more from second skin and am going to finish the header and replace the insulation in the roof and see if I can improve it but even if I can't at least I can get around without having to wear ear plugs! Thanks for all the suggestions, hope I've helped someone else with the same problem.
    Tom
     

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