RE: warped rotors mystery

[Adam Sciortino <A.Sciortino@usa.net>]

Jason_Pankratz@MBnet.MB.CA wrote:
>I have been having trouble for about a year and a half with my
>front rotors.  About one to two months after installation of new
>or machines rotors, they begin to warp.  And warp progressively
>worse.  I have had them replced on four occasions under warranty
>and they always rewarp. The rotors are Brembo brand and I don't
>believe the quality is an issue.  My mechanic is stumped.  The
>parts guy at my shop said that in the twenty years of parts
>service he's given he's never seen anything like this and can't
>figure it.
>
>Any ideas?  Your help would be very much appreciated.

I had the same problem several years ago on my '85 5ks.  I was stumped for
about a year and half.

Are you sure your rotors are warped?  If the symptoms are like those of a
warped rotor (vibration when braking), but rotor replacement or resurfacing
offers only a temporary fix, you are probably suffering from something else.

While it could be, as previously suggested, an out-of-plane hub, that was
not the cause in my case.  It turned out to be a worn tie rod.

The slop in the tie rod connection was apparently so minor that nobody
noticed this problem for over a year.  Everyone pointed at the rotors and
said, "Warped."  New ones were installed twice.  Afterwards, the symptoms
would be hidden for a short while until the rotors got some wear.  Once the
rotors had some wear (only a normal amount, not to the point that one would
usually call warped), this rotor wear worked in concert with the worn tie
rod to produce very noticeable vibration under braking.  It felt just like
warped rotors.

After a year and a half of puzzlement and three shops' unsuccessful attempts
to locate the problem (one in Chicago and 2 in Seattle), Circle Audi in Long
Beach finally figured it out.  Undoubtedly the tie rod slop had progressed
to a more noticeable level when they got their chance to solve the mystery.

New tie rod, problem solved.  That was over three years ago, and I still
have the same rotors.

Hope this helps you Jason.

-Adam
'85 5ks
'89 200q (when visiting my folks)