As far as I know, there are no adjustments or maintainence for this beast. 
As far as troubleshooting, I guess it depends on the problem. They are 
enabled via a vacuum-servo mechanism that is controlled by a switch on the 
dash. If yours is not working, I'd check out the servo mechanism first. If 
that's OK, then the problem is internal to the tranny and is expensive to 
fix. Dennis Haynes (DHaynes57@aol.com) probably knows all about this if you 
need some real help.

-Mark McCulley

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>From: 	Grannegeer@aol.com[SMTP:Grannegeer@aol.com]
Sent: 	Monday, April 08, 1996 7:28 PM

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Date:         
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         
Subject:      troubleshooting rear locking differential on syncro

I need to know how to adjust, troubleshoot, and maintain a locking rear
differential in my 1986 Westy Syncro.  The Bentley only breezes through it.
 I'm wondering if anyone knows of any manuals or literature about it? 
 Thanks
for the info in advance.

1986 Westy Syncro
124,385 miles--still going strong (knock on ze vood)