-----Original Message-----
From: Fred Porter <fporter@EYRING.COM>
To: Vanagon@VANAGON.COM <Vanagon@VANAGON.COM>
Date: Thursday, March 12, 1998 12:50 AM
Subject: Re: Reverse Gear in Syncro

>Leif wrote:
>>
>> I bought an 86 Syncro last week and today when I was backing out of the
>> driveway something strange happened.  I went in reverse for about 20
yards
>> and was getting ready to stop so i put in the clutch and let it keep
>> rolling back a bit when the van just stopped really hard all on it's own
>> (no Brakes on my part) It was as if the transmission locked or something.
>> I've been able to replicate it since but not every time.  Something else
>> related possibly (this is my first syncro) is the fact that the knob on
the
>> console for locking the rear diff.  seems to be exactly opposite of what
>> the owners manual says.  When the knob is PUSHED IN the rear diff. locks
>> and with it pulled out the AWD works.  I deduced this by lighted
>> Transmission diagram.  The light on the rear axle lights up bright when
the
>> knob is pushed in and when it is pulled out the light on the front axle
and
>> in the middle of the diagram are light up ( somewhat more dimly ).  I
pray
>> the Trans is not royally messed.  Any help or experience with the syncro
>> would be greatly appreciated.  I know that they require more care and
>> service vigilance that their 2WD brethren.  Thanks, Leif
>
>Like you said, your indications are the opposite of propper operation.
>When pushed in, the locking rear differential is UNLOCKED and there
>should be no light on in the green drivetrain diag.  When pulled out,
>and engaged, the light in the rear of the diagram should come on.  I
>think the light indicates that the locking diff has locked or unlocked,
>not that the knob has been pulled or pushed.  The locking diff knob is
>used on a vacuum driven switch.  It may be possible that the vacuum
>lines have been switched on the switch or on the vacuum servo at the
>trans.  This may explain why your switch would opperate in reverse.
>Maybe another listmember could verify this possiblity.  I'm hesitant to
>recommend switching the vacuum lines at the trans servo since i'm not
>positive what it would do.  A way to verify that the rear locking diff
>is locked is to drive in tight circles on pavement with the indicator
>light on.  The rear end will lurch because the rear wheels are not
>allowed to spin at different rates to accomodate the different distances
>they travel in a turn.  Don't do this very much as it can be dammaging.
>
>The AWD system (syncro viscous drive) is always connected.  Pulling or
>pushing the knob does not alter its function.  It transfers power to the
>front wheels when the rear wheels spin faster than the front.  See:
>http://www.eskimo.com/~eliot/awd.html
>about AWD systems and a exploded diag of the syncro unit.
>
>Not sure why you are locking up in reverse.
>
>-Fred
>