Date:         Thu, 4 Dec 1997 02:00:52 -0500
Reply-To:     SyncroHead@AOL.COM
Sender:       Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From:         SyncroHead@AOL.COM
Subject:      Re: diff lock/limited slip axle
Comments: To: vw4x4@fyi.net

In a message dated 97-12-02 09:52:40 EST, vw4x4@FYI.NET writes:

> Sorry to disaggree with you but I think an explaination is needed:
> A limited slip rear axle is very simple. It is a conventional rear end
> with a clutch package over top, that locks the 2 wheels together.

"Locks" is not the correct term here.   It doesn't actually "lock" like a
real locking differential.

>If and only if there is to much enough force, such as dry pathment, the
clutches
> will slip, and the conventional axle then works. The slipping happens
> almost all the time as you drive.

Not so.  While driving in a straight line, on dry pavement, each tire travels
an equal distance and equal torque may be applied to each wheel.  In this
case, no slipping is occuring since both wheels are moving at the same speed.
When you go around a corner, the wheels must travel at different speeds and
slippage occurs.  If you have one wheel on ice and one wheel on pavement, you
might be able to transmit enough torque to the wheel on the pavement, but
only up to the torque limit when the limited slip starts slipping.  This
torque is also applied to the wheel on pavement, and you move forward - if
this is sufficient force to move the vehicle.  This depends on many things -
the weight of the car, the slope of the terrain, etc.
Limited Slips are popular with the hot rod crowd to reduce wheel spin on fast
take-offs, like street drag races.  They work well in this application
because both tires have nearly (but not exactly) equal traction.  If the
traction at each wheel varies just a little bit, a difference under the
threshold of the limited slip, both wheels remain "locked" (o.k., I used the
word too.) together and power can be applied through both wheels for faster
accelleration.  Without the limited slip, th wheel with the least traction
will almost assuredly spin, reducing acceleration.

>It could be equated to a CV in a syncro.

Of course you meant to type VC.  Actually the VC operates in just about the
oppisite manner.  It allows small amounts of slip all the time and then lock
up if the slippage becomes too great.

>The problem with them is they were out, and your left with a standard axle.

You're exactly right here!

For more information on many differential types including a variety of
limited slips and locking differentials see W.J.Markerink's page on "Traction
Adding Devices" including th Syncro's VC at:
http://www.a1.nl/homepages/markerink/diffs.htm

Markerink's main page has MANY links to other areas of interest to
four-wheelsers too.
http://www.a1.nl/homepages/markerink/main_4x4.htm

Absolutely worth a look!

Regards,
Jim Davis