hello,
 
firstly we would like = to apologize for posting what is almost the same message twice.  it took a = little while to figure out what questions to ask. what we're trying to find are = answers to questions about the fine points of the syncro part of the vanagon.  = there is a noise(low hum), or vibration that starts at about fifty miles an = hour and is not very loud or distracting (sounds more like the start of a problem = than the end of a part).
 
  the problem that = we are having is that most shops won't look at it, and the ones that will don't = understand the syncro or how it works. we were recommended a mechanic by another = vanagon owner(local). it is a two man shop, the proprietor/head mechanic drives = a mint vangon carat,  the mechanic working for him also drives a vanagon, = and the proprietor/head mechanic's son drives a '91 vanagon syncro. from the = background he described (plus there were four or five vanagons on the lot when we = arrived) we thought for sure that we had found a good person to work on our van. = however, when the proprietor was test driving it, he pointed to the dif-lock knob = and said "have you ever engaged the four wheel drive?" which = belies a major lack of understanding of the basics of the system, which makes us = question his diagnoses. he seems to be a vanagon expert in all other regards, and = we feel confident to have him do the straightforward vanagon work, oxygen = sensor, et al... the tough part is the following.
 
is there anyone we can = write to or call who could answer the questions;
in what way(ways) can = the viscous coupling "go bad"? (fluid locks up early/never locks? plates = get damaged?)
what other parts of the = drivetrain would suffer as a result of this?
what would the symptoms = of damage caused by overly worn and subsequently mis-matched tires(yikes!) be?
is there such a thing as a replacement viscous coupling, what is the = availability, and are they $4000?
would a botched u-joint replacement on a driveshaft put it out of balance, and how would = one go about repairing/replacing it?
what other parts of the = drivetrain would suffer as a result of this?
 
phew!
 
there are a couple of = other minor troubles, rough idle, roller mechanism on door, etc. but these can be = fixed by us or the van mechanic.
 
 
many thanks to all!
thanks for the replies, they are always = informative,and valuable!
moon and brenda
 
86 gl syncro