[torsen] RE: Torsen differential

Dave.Eaton Dave.Eaton at clear.net.nz
Sun Nov 17 04:11:14 EST 2002

the audi torsen can't handle high torque applications?  it handles the rs6,
the largest torque application audi has, ditto the w12 in the old a8...

haldex?  this is the name of a company, not a differential.  haldex makes a
range of (mainly truck-based) equipment - brakes, abs systems, hydraulic
systems etc.

haldex also makes an awd differential, called the lsc.  interested to
understand how audi could have installed it in "full-time awd" mode?
certainly the jeep application you mention is the same lsc unit, in the same
application as audi use.  nvg started using their haldex lsc-based unit for
jeep at about the same time as it debuted in vwag applications.  you can't
call it full-time awd in one, and not the other - because it isn't.

there is no doubt that an electronically controlled lock-up clutch (which is
what the haldex lsc is), it the future of awd systems - cheap, and fully
controllable.  "torque levels virtually limitless" makes no sense.  the
haldex lsc has an overload protection valve - but is not operational at that

'95 rs2
'90 ur-q
-----Original Message-----
From: QSHIPQ at aol.com
Date: Thu, 14 Nov 2002 10:21:19 EST
Subject: Re: Torsen differential

[ Picked text/plain from multipart/alternative ]
A couple points.  First, the Torsen isn't bulletproof, it wears or breaks,
that's all.  It's not meant to handle large torque applications in the audi
application.  Heavy equipment is actually going towards the Haldex systems,
not the torsen systems.  The main reason you see torsen centers is the
ability to use ABS AND EDL with no human interaction.  Current audi applic
ation torsens are 75/25/75 or 78/22/78 in the pre nue S4 cars, depending on
which audi literature you read.


What's "new" in terms of technology?  The haldex.  The Haldex engineers
that audi could use it in "fulltime" awd mode (actually *they* wonder why
audi doesn't do this), and that the torque levels are virtually limitless
(haldex roots is as heavy equip supplier).  Audi is actually late in the
haldex game, since Jeep has been using the haldex type center diff in their
SUV's for a couple years now.

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