[torsen] VC's vs LSC

QSHIPQ at aol.com QSHIPQ at aol.com
Wed Nov 20 11:57:59 EST 2002

In a message dated 11/20/02 3:55:55 AM Central Standard Time, 
Dave.Eaton at clear.net.nz writes:

> btw, it is not a "hadlex vc" either, it's got no viscous component
>to it - i assume that is a mistake?

I wrote:
 >The Haldex IS a VC by definition.  Wet multiplate clutches however 
activated are >"viscous couplings".  A magnetic lockup wet multiplate clutch 
(ala scoobie) is a VC >as well.

Hmm, maybe not as some may read it.  Ok Dave,  I see where you are coming 
from. A Haldex is a LSC, clutch type, as apposed to a LSC, viscous type.  The 
difference as Dave is pointing out, is that a Haldex and other clutch types 
are designed have contact with driveshaft speed differences, the VC are 
designed to affect the fluid viscosity, and the sheer forces of this fluid 
cause non contacting metal plates to transfer torque in a VC, currently not 
Haldex technology.

My apologies for any confusion.  That said, at some point SAE will be 
addressing these issues as well, since this is the "old school" definition of 
LSdevices.  Currently, *including torsen*, fluid viscosity affects coupling 
of all devices, so a torsen would fall into the LSC - hydromechanical gear, 
the Haldex into the hyrdromechanical -clutch, and the LSVC into the hydro 
sheer subgroups in the context of "coupling".  With enough heat, the LSVC 
becomes hydromechanical sheer ("humping").  Hold on, it's not close to over, 
wait till Haldex redefines TBR with torque pressure relief valves.

Ok, Dave, from now on, Haldex Limited Slip Coupling (HLSC) for the "hang on" 
type, and Haldex Limited Slip Coupling Differential (HLSCD) when applicable.  
Fully differentiating until further SAE ruling, the Limited Slip Viscous 
Coupling.  OK?



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