RE: vc vs awd

["Dave Eaton" <Dave.Eaton@clear.net.nz>]

pretty much bang on, except usually the vc is bolted to the outside of the
diff, but takes one set of splines to one side of the diff, and the other to
the other.  this involves 3 shafts through the vc (counting the actual
output shaft itself).

hth,
dave
'95 rs2
'90 ur-q
'88 mb 2.3-16


-----Original Message-----
From: Phil Ethier [mailto:pethier@isd.net]
Sent: Monday, 27 September 1999 14:35
To: Dave Eaton; quattro@audifans.com
Subject: Re: vc vs awd



From: Dave Eaton <Dave.Eaton@clear.net.nz>

>4) if however, you connect a vc to *both* sides of a centre differential,
>then the vc will act in allow interaxle slip while transferring drive to
>both output shafts.  this is a true (albeit complicated) full-time awd
>arrangement with a centre vc.

Stop me where I go wrong:

What I think you mean here is a viscous-coupling using interleaved plates in
silicone or similar liquid.  Small inputs slip easily.  Large inputs cause
the unit to "lock up" and operate without slippage.  This unit is placed in
the center of the differential "cage" in the center differential of an AWD
car.
Small variations between front axle and rear axle pass virtually unnoticed.
When one wheel spins, the VC locks up, transferring drive to the other axle.
What I have just described is the original Jeep QuadraTrac.


Phil Ethier    Saint Paul  Minnesota  USA
Lotus Europa, VW Quantum Syncro, Chev Suburban
LOON, TCVWC, MAC
pethier@isd.net     http://www.visi.com/mac/