Hello!

As some of you know, I have a lumber rack on my truck. Somehow, the aerodynamics of the front bar, coupled with the cab lights, makes the roof vibrate. At freeway speeds, this vibration gets bad enough that I'm getting a humming in the cab that drowns out the engine.

I know that the rack's doing this simply 'cause the vibration/noise disappeared when I had the rack off to paint it. I currently have the headliner out (needs to be re-covered), so I'm looking right at the bare painted metal of the roof. Before re-covering and re-installing the headliner, I'd like to get some insulation on the roof. Is there a good material out there that's designed to minimize vibration? IIRC, Dyna-Mat's designed to do that for speakers, but I could be wrong there.

Any thoughts would be appreciated...and, on top of the vibration reducing stuff, I'd like to put some noise/heat insulation in.

Thanks in advance!

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2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

...anyone?

Won't tell you that Dyna-Mat's a sure cure, but seems like a good way to go. I've used rubberized roll roofing for essentially the same thing in my VW's - mold it with a heat gun - it's much cheaper than Dyna-Mat and you'll need a lot. The best it does is to dull the sound, but a big improvement in something like a Bus.

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89 300E
79 240D
72 Westy
63 Bug sunroof
85 Jeep CJ7
86 Chevy 6.2l diesel PU

"The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane."
Marcus Aurelius

Use some product that will stick to the roof during the hot summer. Read what Dynamat and it's brothers say on the packaging.

All you want to do is change the resonant frequency.

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Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.