FROM: w.j.markerink@a1.nl (Willem-Jan Markerink)
SUBJECT: Re: Limited slip
DATE: Sun, 26 Apr 98 09:44:10 GMT
ORGANIZATION: A1 de Internet Provider uit Twente B.V.
NEWSGROUPS: rec.autos.4x4

In article <01bd775b$f1afc700$d6cf17c4@sakkie.nampak.co.za>,
   "SAKKIE"  wrote:
>
>Many years back when I drove all sorts of all-terrain vehicles under all
>sorts of conditions for the defense force (SADF),  I was taught that the
>diff does not spread its torque evenly
>(50-50) and that your one wheel will always have the tendency to spin 
first
>unless you have an engaged difflock.

>I could be out by a couple of percentage points,  but the normal spread is
>60-40 meaning that the 60% wheel, unless restricted,  will always have the
>tendency to spin first.
>
>Sakkie


The torque-bias of the diff itself has little to do with this, even with a 
clean 50/50 split it is the torque from the drive shaft that causes slip on 
one wheel first (the one that would go up if the pinion would be locked to 
the axle, to give you an idea of the dynamics involved). 
That said, no diff has a clean 50/50 split indeed, simply because friction 
of gears and shafts spoil things....my literature mentions a torque-bias of 
up to 1.5:1 in open diff's, which equals your 60/40 ratio. This is also the 
reason why you can get going again by pulling the parking brake in a 
slip/stuck situation....the same trick works of course a magnitude better 
with larger torque-bias'es, like on a Torsen diff or even an ordinary 
clutch plate LSD.



--
Bye,

Willem-Jan Markerink


      The desire to understand
is sometimes far less intelligent than
     the inability to understand



[note: 'a-one' & 'en-el'!]

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