[s-cars] Re: S6 steering issues (also opening hood)

[Paul Gailus]

Kenny,

I showed this to my dad who is a mechanical engineer and he
said it looked like a failure from tensile stress, probably starting
from stress risers located: 1.) on the root of the thread where
the break occurred on the shaft and/or 2.) on the bottom edge
of the hex-shaped hole. Pits from corrosion at the bottom
of the hole could have contributed to the problem.
A picture of the end of the shaft might help to narrow down
the origin of the failure.

This failure might have been prevented if the root of the threads
and the bottom edge of the hex-shaped hole each had a larger
radius on them. Some grease in the hole to prevent corrosion
wouldn't hurt either.

Paul

----- Original Message -----
From: K G Hayes <abiglizard at att.net>
To: <s-car-list at audifans.com>
Sent: Saturday, December 14, 2002 1:12 PM
Subject: [s-cars] Re: S6 steering issues (also opening hood)


>
> Paul,
>
> I've had the car about 2 1/2 years.  To my knowledge the suspension is all
> stock and I don't know if the struts have ever been replaced.  The struts
> have no blatant manufacturer information (e.g. large letters defining Koni
> or Bilstein).  They seemed to be fine as far as the dampening function
goes.
> The top shock mount has Audi part numbers on it so I'll presume it's all
> stock also.  The failure of the strut shaft was just below the nut on top
of
> the shock mount in the threads.  To look at the end of the separated
strut,
> I could see the bottom side of where the Allen whole was pressed in.  I
took
> a couple of photos and threw up a quick page since we can't attach stuff.
> Click to enlarge photos and you should be able to see more than I can
> explain with my observations.  The photos of the strut under the car don't
> show much except that the shaft is no longer in the shock mount whole.
But
> the photos of the nut show the interesting shape and color of the metal
that
> failed.  If you want other photos taken to look at something else I can
> probably do it before I take the car in.
>
> http://home.att.net/~kenneth_hayes/strut
>
> Kenny