When my driveshaft started to rumble, there were three choices:
1.used 120K driveshaft at the local VW junkyard for $100--figured it
  would die soon also
2.new one for about $800
3.John Dobson at Roseville's German Auto (he works mostly on Mercedes
  from all over NorCal)  strongly recommended, then sent it to a shop that
  cut off the old  u-joints and welded new, greasable ones on.  So far
  it's worked for    another 100K miles.  $400.  He does this on Mercedes
  so he felt   comfortable with it.  I was too dumb to know to be worried.
  Sure is fun greasing those joints.
Cheers, Tom Neal '87 syncro

On Thu, 29 Apr 1999, Dennis Haynes wrote:

> This is probably why VW only sells complete shaft assemblies. they must know
> something. I have had some luck repairing these things but it seems about
> 50/50.
>
> Dennis
>
> -----Original Message-----
> From: Dr. Rainer Woitok <woitok@RRZE.UNI-ERLANGEN.DE>
> To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
> Date: Thursday, April 29, 1999 3:05 AM
> Subject: Problems with the u-joints of the driveshaft
>
>
> >Syncronauts,
> >
> >recently    another German  Syncro   driver  contacted  me  because he's
> >permanently having problems with his drive  shaft.  The viscous coupling
> >was replaced due  to the  grooves  where the  input shaft enters   being
> >totally worn  out.  Later he observed  severe vibrations which he traced
> >back to the drive shaft.   He removed it  and took it  to a special shop
> >for balancing.  After putting the drive shaft  back in everything seemed
> >normal for  a few weeks, but  then the vibrations  were back.  Currently
> >he's driving with the drive shaft removed.
> >
> >Some months ago we had a discussion on this list about universal joints,
> >and I faintly remember that at least one  person mentioned that when you
> >mount the u-joints onto a shaft the wrong way you're into trouble due to
> >the different rotational  speeds occuring at the  different  ends of the
> >shaft at different times and thus placing severe stress on the material.
> >
> >I've never yet disassembled my drive shaft, so my  question here is: can
> >one mount the  u-joints on a Syncro's drive   shaft the wrong  way?  And
> >what has a Syncro's drive shaft  with correctly mounted u-joints to look
> >like?  And could a wrongly assembled drive shaft cause these vibrations?
> >Or should he check for other causes?  Which ones?
> >
> >Any input will be greatly appreciated and passed on to the owner of said
> >castrated Syncro :-)
> >
> >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 |
> > ----------------------------------------------------------------------
>