Date:         Tue, 20 Aug 1996 12:45:49 -0400 (EDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         ERIC ZENO <emz@viper.nauticom.net>
Subject:      Re: Warning:To Syncro owners


On Tue, 20 Aug 1996, Tim Smith wrote:

> 
> Eeeeek!
> 
> What RPM? or speed? 
       I was going about say.... 20 mph.
  
  any idea, it shouldn't have overrevved, the FI would
> shut off the gas nicely (BTDT), and the engine braking should be sufficient
> to prevent runaway I presume...  so I'm lost.
>
       The clutch pedal was in. Motor was at idle.
 
> I'm guessing the clutch disc had a lot of cracks in it, and finally let go
> at higher but normal RPMs. If you look at some pieces where they broke you
> may be able to see 'beach marks' like the sand ripples on a beach.  These
> show the growth of fatigue cracks (like tree rings)  The surface appears
> dull gray, where the metal has been progressively parting.  Once it lets go
> the metal should appear more jagged, since it's tearing apart fast.
> Finally, if there are small areas silvered over this is where the loose
> pieces have been bumping into one another.  So, longterm slow failure should
> show beach marks + tear zone (maybe +silvering), quick failure is tear zone
> only. Any chance the pilot bearing in the hub is out to lunch too? Although
> this is not attached to the disc it keeps the shaft/disc centered and
> spinning properly.  It _may_ be a factor.  Keep us posted, this could've
> been real nasty shifting from 3rd to 4th on the highway at 55+mph!!!!
> Thanks, glad no personal damage.   tim
> 
    I think it was just stupid of me to keep it in Creeper gear with the
    clutch in. At 6:1 gear reduction, times 1st gear Rpm, at 20 mph,
    the disc was flying. I think the G-force would distroy any disc!
> 
    Oh Well another week of work to add to the list!

                                   ERic ZEno