Malcolm, first off I'm not an expert but we have a Syncro Westfalia and when
we first  got the van we did have a lot of trouble with the Differential Lock
not locking.

Malcolm Stebbins wrote:

> The 'plunger' into the tranny seems to work OK as does the servo unit.  Is
> it
> possible to hook up a manual (choke like) cable to the diff-lock unit ??

The plunger needs to be pushed to engage and pulled to disengage so a cable
may not be the best choice.

>   2)  What is the advantage of a vacuum activated diff-lock switch?

I believe that the entire vacuum system (vacuum tank, vacuum dash switch,
vacuum servo) only serves this diff-lock. It seems that even a solenoid
switch (like the solenoid on the starter) would have been simpler.

>     3)  the diff-lock vacuum bottles lines (or Y connectors) were making a
> whining noise so I have blocked them off with golf tees.  Am I doing any
> harm?  Please keep in mind that I'm running carbs not FI on my '91 syncro.

IMHO you are doing no harm but just the vacuum line to the intake manifold
needs to be blocked off. Everything after that is fed from this line.

Larry
'86 Syncro Westfalia (with FI)