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 |
>  ----------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------
> You can now easily share photos and documents with your fellow list
members
> http://www.ONElist.com
> Check out our homepage for details on how to use our new shared files
feature!