Sounds like one of the classic ways the transmission can die.
Time for a rebuild.

-craig

On Oct 5, 2012, at 8:17 PM, mark drillock <mdrillock@COX.NET> wrote:

> You should refer him to the South African Syncro group on Yahoo. They
> are pretty active.
>
> http://autos.groups.yahoo.com/group/SyncroSA/
>
> Mark
>
>
>
> John Meeks wrote:
>> Hey list folks,
>>
>> I got an email from a guy in South Africa with a  '90 Syncro. He asks: ' A
>> problem popped up that I do not know how to deal with. While driving on
>> highways the gearbox pops out of fourth gear.  Is this something that will
>> have to go in to a (very expensive) workshop and rebuild exercise. That
>> said, I live in South Africa where spares for these vehicles are
>> non-existent.'.
>>
>> Any ideas to address this issue?
>>
>> John Meeks
>> '91 Vanagon MV Phoenix
>> Northern Michigan
>>
>> Vanagon Rescue Squad
>> www.vanagonauts.com
>>