RE: locking diffs?

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

the haldex (tt, a3q, s3) in the vw/audi appplication is used as a "hang-on
clutch", in the same way as a number of manufacturers use a viscous (vc)
unit.  this means that torque is not transferred until the axle (usually
rear) requires it.  so, although technically it is accurate to describe it
as "full time" awd (in the sense of not requiring any intervention to
operate), it is not what a lot of people would call "full time" awd (in the
sense of have both axles driven all the time)...

the haldex has the advantages over the vc of quicker initiation and full
software control (e.g. programmable locking/unlocking rates).

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

-----Original Message-----

Date: Wed, 11 Aug 1999 02:39:08 +0100
From: "Damon Cassell" <dcassell@bbnplanet.com>
Subject: Re: locking diffs?  was: Boating with an S4

ah okay, well here's another question then..

you mention that it's all wheel drive, all of the time.  so, this is unlike
the AWD systems on a Honda CRV or a subaru, right?  i believe those systems
are primarily FWD but direct a certain percentage of power to the rear
wheels when necessary.  all four audi wheels are powered simultaneously even
on a flat, dry surface?

damon