We have a fair bit of
misinformation in this posting on another (non-Syncro) site:
I’m not too sure what they are exactly called but today I fitted a T3 4WD
locking kit that gets rid of the Viscous coupling (known for failing), It
replaces the viscous coupling with a long metal splined tube, then on the
gearbox there’s a mechanical switch (hard to explain how it works) to
switch it to 4wd or rear wheel drive. It switches with the same system used for
the diff locks. Apparently Volkswagen were going to use this system originally
but bailed out and chucked a viscous coupling in, you can see evidence in the mouldings of the back piece
of the gearbox (You replace it with a hole new rear piece with the locking
mechanism in it). If you have a T3 Syncro and your viscous coupling seizes up I
recommend to get it instead of paying $1500 for a viscous coupling off Volkswagen
that will probably screw up in 5 years time again. The customer went over to
bought it back with him but I’m sure you can get it sent here somehow.
Anyone else ever heard of this system?
The VC probably has a
service life of around 100,000km or so but there are a lot of Syncros with well
over 200,000 on the clock and still running the original VC. Indeed, VAG
originally had a direct drive to the front wheels that could be mechanically
decoupled from the dash. Since this limited the use of four wheel drive
to off-road only, they replaced the solid shaft with the VC, this giving more
than adequate four wheel drive performance over an extremely wide variety of conditions.
They kept the solid shaft as an option but never even advertised the fact for
the production life of the vehicle.
It is a characteristic of
the VC that it comes into operation progressively earlier as it wears,
producing what is generally described as an “aggressive”
operation. Whilst this earlier operation of the VC has significant
benefits in terms of handling and braking, it causes some binding when making
full lock turns on a high grip surface, usually experienced in parking, thus
adding a significant load to the driveline and particularly the gearbox. Using
a decoupler avoids this excessive loading. I prefer the characteristics
of the aggressive VC in terms of enhances handling and braking.
The solid shaft CANNOT be
used on normal bitumen roads (it destroys the gearbox) and the enhanced
characteristics of four wheel drive are available only on gravel roads and bush
tracks. (It also works very well on sand.)
The VC system, as
designed by VAG and Steyr Puch, was a world first and works extraordinarily
well. It drew unprecedented attention in the world of professional motor
vehicles engineers. (Anecdote: I was seconded from Holden to HSV to
engineer the HSV Coupe4 at the same time that I bought my Syncro. I
turned up in the Syncro and people came out of the woodwork (including the
racing team) to look at it. I was able to demonstrate its capabilities on
some of the landscaped mounds in the grounds. The HSV fleet manager later
told me that a lot of rather exotic vehicles turn up at HSV but the humble
Syncro had pulled more than the rest put together!)
Some people acquire a
Syncro with the preconceived idea that it “needs” improvement or,
in other words, it can’t possibly be as good as people say it is.
Well, it is!! Which is why I say to people ‘take it out into the
roughery and find out what it can do bog standard before deciding that it “needs”
tractor wheels, two feet of ground clearance and a six litre V8.
Most of the retail
Syncros in Australia
came with a rear diff lock and they are capable of going anywhere a sane person
would want to go. Anyone who feels that their Syncro is seriously lacking
and who has unlimited funds should save themselves a lot of time, buy a
Pinzgauer and be done with it.