I am re-posting this from Warren Chapman in the US . There has been considerable discussion about driveshaft vibrations on the various Syncro websites around the world for many years but this is something new, something that has not come up before as far as I know. Worth looking into, I suspect.
Syncro@yahoogroups.com [mailto:Syncro@yahoogroups.com] On Behalf Of Warren Chapman
Sent: 18 July 2009 06:35
Subject: [Syncro] Driveshaft Vibrations.......Happy Story !!
I had a syncro with significant driveshaft vibrations. I bought the van when the PO tried two different new driveshafts. ...one, a split yoke...with no success. The vibrations were significant enough that I pulled the driveshaft and have been driving around without it.
It's amazing all the different complicated and hugely expensive solutions were suggested by several Vanagon specialty service shops in the SF Bay area and I also explored all the "wiz bang" lazer flange alignment options....but never could quite figure out how to use the damn thing. GoWesty sells a version of this device for over $300 but when asked how it was designed...I was told it's specifications were simply taken off a van that didn't vibrate....no complicated trigonometry formulas.
I've been saying to myself...it just can't be this hard....or there'd be a big section in Bentley...and mention of specialty tools that a dealer would have.
Props to Peter at Van Cafe. I called and asked him what they did when a Syncro came in with vibrations. He told me they simply put the driveshaft in....loosen the mounting bolts to the front diff and take it out and drive it....and let it sort itself out.
I did the same........ VIBRATIONS GONE!
Hope writing this publicly doesn't cost Van Cafe some big money fixing Syncros that vibrate.
YMMV....but I'm a happy camper.