Rear Deck Vibrates
Thread Starter
Instructor
Joined: Mar 2003
Posts: 195
Likes: 0
From: Eagle Wi
Rear Deck Vibrates
Got a 77 (last year of the square back) and there are certain exhaust resonances that just get the rear deck just buzzing.
Drives me crazy.
You can reach back and put some upward pressure with your hand and it will stop. I know it's the top of my rear compartment that's doing it.
Any suggestions on how to stiffen that up or anything that will keep it quiet? The car is pretty loud and it comes right through it all.
Drives me crazy.
You can reach back and put some upward pressure with your hand and it will stop. I know it's the top of my rear compartment that's doing it.
Any suggestions on how to stiffen that up or anything that will keep it quiet? The car is pretty loud and it comes right through it all.
Thread Starter
Instructor
Joined: Mar 2003
Posts: 195
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From: Eagle Wi
Originally Posted by norvalwilhelm
Dynamat is designed to take the resonance out of flat surfaces like that. Also duct insulation is self adhesive and should help.
I'm talking about the roof in the back compartment. Do you think Dynamat would stop the vibration? It's pretty bad. I know that stuff is made for (I think) stereo installations and the bass frequencies but my exhaust would put any amp to shame.
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Safety Car
Joined: Aug 2000
Posts: 3,943
Likes: 44
From: Florham Park NJ Port Credit Ontario
On my 74 it was a combination of things.
1) Chambered exhaust
2) Gas door vibrated..fixed with new rubber bushings.
3) Deck vents vibrated. Fixed by meticulously tightening every single screw I could find...inside the car and out!
1) Chambered exhaust
2) Gas door vibrated..fixed with new rubber bushings.
3) Deck vents vibrated. Fixed by meticulously tightening every single screw I could find...inside the car and out!
Pro
Joined: Aug 2002
Posts: 560
Likes: 0
From: The Valley of The Sun AZ
Take it off and run a bead of clear silicone on the mating surface, let it dry and re-install. This will stop rattling. I use it all the time when I have a squeak between two hard surfaces. You can also use felt.
Melting Slicks
Joined: Nov 2003
Posts: 3,363
Likes: 0
From: Canton Ohio
Originally Posted by tersian
Take it off and run a bead of clear silicone on the mating surface, let it dry and re-install. This will stop rattling. I use it all the time when I have a squeak between two hard surfaces. You can also use felt.
Burning Brakes
Joined: Mar 2003
Posts: 891
Likes: 165
From: Oswego IL
The rear deck vents on my 74 used to vibrate and rattle terribly. I went to Home Depot and bought some tiny rubber o-rings. I placed the screws through the vent screen, and then placed the o-ring over the end of the screw and tightened everything down. It fixed the problem for me.
Thread Starter
Instructor
Joined: Mar 2003
Posts: 195
Likes: 0
From: Eagle Wi
I don't have anything on the roof yet. I was thinking about gluing an aluminum brace across the surface.
If something like insulation would work that would be preferred as it might cut down the outside noise also. I just never though the stuff would be stiff enough to stop a vibration.
What do you guys think of a small aluminum I-beam to the underside of the upper deck and held on with something like liquid nails?
Something small that would not be very noticable.
If something like insulation would work that would be preferred as it might cut down the outside noise also. I just never though the stuff would be stiff enough to stop a vibration.
What do you guys think of a small aluminum I-beam to the underside of the upper deck and held on with something like liquid nails?
Something small that would not be very noticable.
Le Mans Master
Joined: Nov 2004
Posts: 7,186
Likes: 45
From: detroit area
a few layers of dynomat will stop that... i did my whole interior with dynomat...... make sure to clean the surface and use a heat gun once stuck to the roof and heat it a bit to help make it stick better....
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