I'd be interested in performing this test but being mechanically
dyslexic, I could see the front wheels grabbing, the rears coming
down and the floorjack end-over-ing or the extended part  puncturing
some underside part of the van.

My question: where do you place the jack and how keep the van from
rolling foward if the VC is working?

Kevin

-----Original Message-----
From: Brent Christensen <bpchristensen@MINDSPRING.COM>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Wednesday, April 21, 1999 9:28 AM
Subject: Viscous Coupling survey

>I think it would be interesting to see how many of the Syncros out there
>will idle freely at 1,000 rpms with the rear wheels spinning in the air and
>not engage the front wheels.  If you have a Syncro and a floor jack with
>wheels it is a relatively simple test.  If you have time, please try it and
>report back to the list.
>
>My Syncro will engage the fronts at the  full 800-1,000 rpm idle speed, but
>if I slow the rear wheels down a bit using the hand brake, then the fronts
>will disengage.  I wonder if my VC is toasted...  ???.  (The fronts grab
>while making sharp turns in parking lots, but don't seem to act up at
"road"
>speeds.
>
>Brent Christensen
>'89 GL Syncro Westy
>'91 Taurus SHO (For Sale)
>'95 Cherokee Sport
>
>----- Original Message -----
>From: Dr. Rainer Woitok <woitok@rrze.uni-erlangen.de>
>To: Joel David Shortlidge <shortlid@expert.cc.purdue.edu>
>Cc: Steve <Steve@Schwenk-Law.com>; <wt@iscnet.co.uk>; <Syncro@onelist.com>
>Sent: Tuesday, April 20, 1999 3:55 AM
>Subject: [Syncro] Re: Viscous Coupling
>
>
>> From: "Dr. Rainer Woitok" <woitok@rrze.uni-erlangen.de>
>>
>> Joel and all others,
>>
>> On Mon, 1999-04-19 15:55:41 -0500, Joel David Shortlidge wrote:
>>
>> > ...
>> > How can you tell your VC is frozen???
>>
>> VW's original (German) repair manual doesn't say much  about how to test
>> the viscous coupling.  They only recommend placing the  rear wheels in a
>> break testing stand.  If you then switch to  the G-gear (creeping gear),
>> the front  wheels should move the van  out of the  test stand as soon as
>> the engine is revving slightly above idle.   If the front wheels fail to
>> do so the viscous coupling is to be replaced, VW  says.  VW adds another
>> tiny sentence  to this, saying that only  when the engine  is revving at
>> idle and with the G-gear  switched in, the viscous  coupling is able  to
>> absorb all the torque to the front wheels and keep them from moving.
>>
>> To me  this   last and  rather   ill-formulated (in the  German  manual)
>> sentence is the key to testing the viscous coupling.   For in most cases
>> we  are not dealing with viscous  couplings doing less than their share,
>> but rather with hard-going viscous couplings  which don't have a problem
>> at all in  moving the van  out  of the  test stand with  the engine just
>> idling.
>>
>> Thus the really important thing here is not the van successfully leaving
>> the test stand.  On the  contrary, the important thing  here is the  van
>> not moving and staying put in the test stand with the G-gear switched in
>> and the engine just idling.  If your  Syncro doesn't pass this test your
>> viscous coupling is probably  worn out and  ready for a replacement.  Or
>> put  the other way  round: as  long  as your van's  viscous  coupling is
>> working properly you will not notice your van has got one.
>>
>> As   soon as   you are encountering   problems   with your Syncro   when
>> cornering, in particular after a long and  fast drive, or  as soon as --
>> despite  of power  steering --  steering becomes   a  bit difficult when
>> turning and the Syncro slows down considerably when going round a corner
>> ... as soon as one or  more of these  things are happening, your viscous
>> coupling is most  probably due  for  replacement.  When  the tires start
>> whining while cornering it might well be too late already ...
>>
>> Hope this helps.
>>
>> Sincerely
>>  Rainer
>>
>> '89 Caravelle GL Syncro 16"
>>
>>  ----------------------------------------------------------------------
>> | Rainer M Woitok                  | Phone: (+49-9131) 85-27811,-27031 |
>> | Regionales Rechenzentrum         |                                   |
>> | Friedrich-Alexander-Universitaet | Fax  : (+49-9131) 30 29 41        |
>> | Martens-Strasse 1                | Telex: d 629 755 tf erl           |
>> | D-91058 Erlangen                 |                                   |
>> | Germany                          | Mail: Woitok@RRZE.Uni-Erlangen.DE |
>>  ----------------------------------------------------------------------
>>
>>
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