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Vibration under hard acceleration

Greyhorse

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While under hard acceleration im getting a vibration , the car is lowered on eiback sportlines, got bmr cradle lock outs steeda irs bushings and steeda irs braces car is roush blower pbd tuned 10r80 trans. Id say its been doing it under hard acceleration it was noticeable but now since tuned and taken to tge track i could really feel it was wondering if the pinion may be oscillating up and down possibly and a pinion support is needed. Anybody have anything similar under boost/hard accel????
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Gregory347

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I had similar issue caused by aluminum differential bushing inserts.... swapped for Whiteline KDT934 inserts and car is smooth again... vibration and harshness eliminated
 
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Greyhorse

Greyhorse

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I think i found the culprit. The center carrier bushing on the drive shaft is so soft i can move the driveshaft easily in any direction at least 3/4” , a one piece drive shaft has been ordered (10weeks out) im sure that got to be it if i can easily move it around then i can only imagine how much more it is moving under load.
 

codereddew

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I think i found the culprit. The center carrier bushing on the drive shaft is so soft i can move the driveshaft easily in any direction at least 3/4” , a one piece drive shaft has been ordered (10weeks out) im sure that got to be it if i can easily move it around then i can only imagine how much more it is moving under load.
confirmed this was the culprit/worked?
 
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Greyhorse

Greyhorse

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confirmed this was the culprit/worked?
Havent yet been to a track but i did put headers on and found a motor mount loose where the dealer had replaced the drivers side prior and have installed the new driveshaft so hopefully it is gone. Might have been the motor mount as it was done by the dealer between trips to the track and right after they worked on it is when the vibration started
 

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Rapid Red

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Was going to ask about the drive shaft. But sounds like you're in the right camp.

One question, has it been removed, know about witness marks for the install ?

I just learned about that one.
 
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Greyhorse

Greyhorse

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Headers?
 

bnightstar

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Havent yet been to a track but i did put headers on and found a motor mount loose where the dealer had replaced the drivers side prior and have installed the new driveshaft so hopefully it is gone. Might have been the motor mount as it was done by the dealer between trips to the track and right after they worked on it is when the vibration started
did a driveshaft fixed this for you ? I have a vibration harsh during acceleration in 5th only and I suspect is a driveshaft.
 
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Greyhorse

Greyhorse

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Yes it mainly but i also had cupping on my front runners they actually called for like 90psi i think?? I think ran them at like 70-80 cant remember but originally i drove around with 32psi in them and my camber was off so it cupped the inside of the tire pretty good so bought new front runners so i think some came from both but i would have done the 1 piece ds either way not that im that fast and the auto instead of manual but feel better knowing i got a better ds. My 60’ times in the 1.4x’s and im runnin 6.3x’s in the 1/8th on e85 and stock pulley now
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