[s-cars] Problem vibration in the front end?

[qshipq at aol.com]

 Remember Colin, the order I gave said brake pistons 'first'  :)....  Doing them last is ok too.  The last time I worked on the SQ brake calipers, IIRC they do not have a weather seal ala porsche 993 et.al.  This can cause piston deterioration which then leads to a 'stuck' piston usually due to pitting or dissimilar metal galling.  The set I did required new seals and new pistons in front.  IIRC II, you can get various metal replacement pistons for the SQ brakes, including Stainless, but they are pricey.

Good luck

Scott J

 


 

 

-----Original Message-----
From: colin cohen <ccohen5 at compuserve.com>
To: s-car-list at audifans.com; qshipq at aol.com
Sent: Fri, Nov 5, 2010 5:48 pm
Subject: Re: [s-cars] Problem vibration in the front end?


Scott your suggestions have gelled with the advice I have had from many and I have checked all the joints and bushings for play. All are OK.  The brake retraction question is still in the air because there has been a problem with this 10 years ago that has forced me to confine my pad choice to the stock specification.  Almost any other produces a wailing sound at slow speed from the driver front side that in now believe is a piston issue.  The stock pad being softer may simply be scuffing as evidenced by slightly more dust on the driver side wheel than the passenger.  So I am definitely going to look into that although there is no noticeable drag on that wheel.
 
Strut bushings were replaced with the shocks which initially had seemed to be the problem.  But this did not fix it.
 
Will keep at it.
 
Colin
  
----- Original Message ----- 
  
From:   qshipq at aol.com 
  
To: ccohen5 at compuserve.com ; s-car-list at audifans.com 
  
Sent: Wednesday, November 03, 2010 9:07   AM
  
Subject: Re: [s-cars] Problem vibration   in the front end?
  


  
Colin
The symptoms you describe identify a couple items to check, and   suggest doing it in this order.  First, make sure all your brake pistons   are fully retracting.  Second, take a pry bar and check for play in the   control arms/subframe.  Third, check to make sure the ball joints are   tight in the control arms themselves.  Lastly, look for play in the upper   strut bushings.

Scott J
QSHIPQ



  


  
  


  


  
-----Original   Message-----
From: colin cohen <ccohen5 at compuserve.com>
To: Paul   Gailus <gailus at mindspring.com>; Audi S Car List   <s-car-list at audifans.com>
Sent: Wed, Nov 3, 2010 7:24 am
Subject:   Re: [s-cars] Problem vibration in the front end?

  
No sign of an alignment problem with no sign of tire scuffing.  I had 





thought about caster but the it would have to be excessive for vibration and 





would be evident throughout the speed range.











Its not an instability or dartiness caused by toe out.  Plain and simple 





wheel oscillation as one would find with a major wheel imbalance.  But its 





not that as the wheels have been swapped and changed.











The Sq is really an Urq that took an incomplete dose of steroids.  Audi had 





to build them this way to meet Piech's budget constraints: the road cars had 





to pay for the rally ones.











Colin





----- Original Message ----- 





From: "Paul Gailus" <gailus at mindspring.com>





To: "colin cohen" <ccohen5 at compuserve.com>





Sent: Tuesday, November 02, 2010 6:58 PM





Subject: Re: [s-cars] Problem vibration in the front end?