Date:         Fri, 8 Jan 1999 13:09:54 -0700
Reply-To:     "Kanas, Jon B" <jon.b.kanas@LMCO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Kanas, Jon B" <jon.b.kanas@LMCO.COM>
Subject:      Transmission/Differential Lubricant
Content-type: text/plain

Good Afternoon,

I'm looking for a response from one of you who is an expert on the Syncro
driveline, specifically for a 1987 Westfalia Syncro.  I changed by rear
transaxle oil recently, at 90K miles.  I put 80W90 Mobil 1 synthetic gear
oil in it, and it's been great.

The oil which was removed from the transaxle was really BLACK.  I've never
seen oil that dirty in a transaxle before.  I was concerned, so I figured
that I should probably change the oil in the front differential also.  I
haven't done this yet, since I didn't have enough oil to do both at the
time.

I wasn't sure of the capacity of the front differential, and I wanted to buy
oil on the way home from work, so I called a local dealer;  here's where the
problems begin (isn't this a big surprise??).  Based on what seemed like
uninformed (and not real reasonable responses) I called another dealer.  I
received a whole new, unrelated set of what sound like wrong answers.  I now
ask for some information from some of the more well-informed on our fine
list for assistance:

1)  The Syncro has a front differential, which is different from the Viscous
Coupling, correct?


2)  This differential contains a lubricating liquid, something along the
lines of 80W90 gear oil?


3)    I can, in fact, change this lubricating liquid without, in any way,
effecting the Viscous Coupling?


4)   How much of the lubricating liquid will I remove and replace?
Something around 1.6 liters?


5)   Is anyone on the list using synthetic gear lube in the front
differential?   Is there any reason to believe I will "score the cones" by
using synthetic gear oil?


When I called the two dealer(s), I was told the following 'facts', most of
which did not pass my reasonableness edit, unless my understanding of both
the Bentley manual and the general mechanical layout of the Syncro is
grossly incorrect.

One dealer said to never change the stuff in the gearboxes.  I could top it
off, but not change it.  They seemed genuinely concerned that I had changed
the oil in the transaxle.  They said it was full of special, very expensive
stuff (which they could not name), and that if it ran low, the coupling
would need replacement.   I was unaware that there was some continuous
hollow cavity, running through the drivetrain of my Syncro, which if low on
mystery lubricating fluid, must be replaced for a significant number of
dollars.  Dismissing this entire discussion, I tried another VW-only dealer.

The second dealer said that there is, in fact, a front differential with
gear oil in it like the transaxle.  They said that the oil should be changed
every 30K miles, but never use synthetic because it will score the cones.
Cones?  I do not pretend to be a differential expert, but I have never heard
of cones in a differential.  I remember something about cones in the
infinitely-variable automatic transmission that a neighbor's Subaru Justy
had....

Maybe I'm just plain nuts.....  =:-p


Jon B Kanas

Lockheed Martin Corporation
Flight Systems Spacecraft Test Lab
303-977-6354
jon.b.kanas@lmco.com