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Old Mar 19, 2010 | 09:43 PM
  #1  
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SST Decel vibration

It has been getting worse for the last 6 months. I notice it in more in "manual" mode than "auto" mode due to the tranny downshifting itself.

When I let off the gas in 6th and 5th gear as the car slows down w/o using the brakes, I get a vibration from under the car that you can feel everywhere in the car. It is worse on 5th than 6th. It is revs dependant.

It happens mostly around 3000 and then goes away as the car slows (revs drop) and then picks back up around 2400 revs. But only noticeable when off the gas. It may be there under accelleration but harder to tell.

I can barely feel it in 4th.

Anybody else have this issue?

I wonder if I have lost a drive shaft weight?
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Old Mar 19, 2010 | 09:55 PM
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nope i have that vib too
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Old Mar 19, 2010 | 10:02 PM
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Engine harmonics?
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Old Mar 20, 2010 | 07:45 AM
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I also have that same vibration.
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Old Mar 20, 2010 | 08:32 AM
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Same here. I always thought it was from the exhaust. It seemed to be less noticeable with a test pipe. I thought the cat was causing some strange resonance at certain rpm
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Old Mar 20, 2010 | 01:08 PM
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resonance within the design of the car. add some dynamat and it'll change the rpm when it happens, but there's always gonna be a point where the rpm of the motor is the right frequency to make the car feel like its falling apart. anyone see the mythbusters episode where the 6lb weight made the san-fran bridge vibrate???

on my car, before i put the downpipe on and only had the tp/cbe, it was weird cause not only would i hit that point of resonance, but it was also the only drone point for the exhaust. i put the car throughout all different driving conditions, to see if i could get the exhaust to drone, and it would only do so at around 65-75mph on decel without braking. so at that point, it seemed like all hell was breaking loose. lol. once the dp went on, its gone. now i have done some other stuff to the car too, and it seems that on accel i get that vibration problem right around 2750rpm under light throttle, but other than that, nothing. its always gonna be there to some extent
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Old Mar 20, 2010 | 01:55 PM
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I thought i was the only one
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Old Mar 20, 2010 | 03:14 PM
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yea! i get this all the time.. also in light throttle it happens like 03chi stated
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Old Mar 20, 2010 | 03:24 PM
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It's the luxury of being on 6th Gear at 35mph :-)
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Old Mar 21, 2010 | 07:34 AM
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Yea I also get it under hard accel in 2nd hear after my O2/dp and TP were installed.
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Old Mar 21, 2010 | 08:47 AM
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Originally Posted by Kieffer87
Yea I also get it under hard accel in 2nd hear after my O2/dp and TP were installed.
I had it before I installed anything
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Old Mar 23, 2010 | 01:23 PM
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This is the exact symtom i had before they swapped the tranny. And the new one they put in still does it. Dealership told me if was "normal driveline vibrations"

Enjoy
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Old Mar 24, 2010 | 07:08 AM
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Why was the tranny swapped?
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Old Mar 24, 2010 | 06:55 PM
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Vibration from the awd and harmonics. Nothin to worry about.
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Old Mar 25, 2010 | 09:27 AM
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From: The Cold North
Originally Posted by laksman91
Why was the tranny swapped?
The shaking on the first transmission was considerably worse than what the second one is producing. The vibration was actually causing a very noticable sound through-out the car and enough to rattle change/sattelite radio on the front window/reveiw mirror.

The second one produces no audiable sound but you can still feel it at certain speeds in certain gears. But no question not as bad as before.
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