My resonance done left me and I ain't blue


Grouchy Old Guy
Established Member
Aug 29, 2010
Central Valley, CA
Standard equipment on GT500s is a harmonic resonance from the rear axle. To combat this feature Ford hung 9.5 pounds of iron on the rear housing ends. To get rid of resonance, you have to tune out the frequency. I changed my R&P to a 3.73 and noticed no difference. When I put in my TrueTrac, I aquired a cyclical "moan", soft to loud repeating at certain speeds. It was speed related on any road surface, but it wasn't gear noise. That wouldn't be cyclical. With the high tech axle weights on, it was a low frequency. With them off, it was a little higher pitch. I thought the TrueTrac was an "untuned for" frequency. It wasn't terrible, so I just lived with it. Recently I saw a paragraph in the Rock Auto Newsletter. It was for a brake noise damper made by Raybestos in Sweden (not China). Well, Raybestos is a reputable company, so I figured I'd try it. They come one in a package and you need two (~$60 including shipping). They take less than ten minutes per side to install, and if you've got ramps you don't even need to remove the wheel.

Conclusion: Without the Ford weights there's a faint resonance between 55 and 60 mph. The rest of the time it's quiet. With the Ford weights it doesn't work as well.

For a picture and video, go to:
RockAuto August Newsletter

Raybestos part number for the GT500 is H14354.

Who woulda thought it was brake noise!
I'm sooooo happy!



New Member
Established Member
Aug 12, 2011
For the high tech axle weigths are you talking about the curved blocks that are mounted with a bolt on the inside of the rear axle by where the LCA mounts? So you removed those and did not notice much difference, but then you installed the brake dampener and it got better?


Resident Man Dime
Established Member
May 17, 2005
South Jersey
Mine are gone also and I notice zero change in NVH or rear end whine. I'm pretty sure my problem is gear noise(existed before ditching the axle weights and remains just the same) , but I may give these shot anyway.

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