Date: Fri, 13 Mar 1998 16:15:45 +0100
Reply-To: Philippe Oudot <p_oudot@WORLDNET.FR>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Philippe Oudot <p_oudot@WORLDNET.FR>
Subject: Re: Reverse Gear in Syncro
Content-Type: text/plain; charset="us-ascii"
At 08:29 12/03/1998 -0700, you wrote:
>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
Howdy listees,
Fred said that you can switch the vacuum lines at the trans servo. That's
perfectly right, I've done that on my rear diff, the front works fine, and
that's it! Nothing else to do. Hope that helps.
Philippe Oudot
'89 Syncro TD Oettinger 16"
French Syncro Club
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