Re: [tech] limited slip

[Dan Bubb <jdbubb@ix.netcom.com>]

My experience, from laying under the car and torquing axle bolts, is
that it doesn't take much force to turn the wheels in opposite
directions with the "factory limited slip." It seems large when it's on
the bench cause you're turning the drive flange so your torque arm is
only 2".
Let's take a quick look at some numbers relative to the "factory limited
slip" Assume it takes 20 lbs force, applied at the tread, to turn the
wheels opposite directions. (I think this is a generous number, but
haven't measured it.) 20 lbs X ~ 1 ft. radius is (tah-dah!) 20 ft-lbs
torque. (Note: this value doesn't change based on load!)
Now even the most pathetic JH makes 100 ft-lbs at the crank. Multiply
this times first gear, times the final drive and then subtract 15% for
losses and you end up with  ~1155 ft-lbs at the wheels.
So, the "factory limited slip" can redistribute 20 ft-lbs of the
available 1155 ft-lbs. Or, to restate, it can redistribute 1.7%.
For comparison, a quaiffe or torsen differential can redistribute ~80%!

Personally, I think we should stop refering to those pathetic springs as
"factory limited slip"??

As far as the ring gear rivets, I don't know if the AGB still had the
problem, but I'd do it anyway and while I was in there I'd inspect the
bearings (especially the small tapered bearing next to the pinion gear),
measure the synchro ring gaps, and install new seals and gaskets.

Dan

Rick Alexander wrote:
> 
> Ok, this begs a question.
> 
> I have an 020 AGB that I removed from an '86.5 16v. My plan is to use it in
> a '86 Cabby with another 1.8 16v.
> 
> While cleaning this up I noticed that by hand I can't move the cups
> independently of each other. I said to 'self, "Wow might be a Quaif or
> something in there. Better break this puppy open and see what's up".
> 
> Question is, could the factory limited slip be that strong?
> 
> While we're at the question game, is this differential subject to the ring
> gear rivet problem and should I break the case anyway to upgrade to bolts?
> 
> Any other suggestions while it's on the bench?
> 
> Rick Alexander
> http://www.brubakerbox.com
> http://clubs.hemmings.com/hams/
> http://clubs.hemmings.com/vwsrus/
> 
> The factory limited slip that is in my 020 ???
> ----- Original Message -----
> From: "Dan Bubb" <jdbubb@ix.netcom.com>
> To: "Mash" <type53@yahoo.com>; "Benjamin Harder" <vwtype53@yahoo.com>;
> <scirocco-l@scirocco.org>
> Sent: Tuesday, September 25, 2001 5:55 PM
> Subject: Re: [tech] Attn: MK1 16v owners
> 
> > It's not much of a limited slip! It's just a couple of springs keeping
> > things from rattling around in there.
> > Which is just saying that not having this feature is not much of a
> negative.
> > Dan
> > >
> > > The FF does not have the factory limited slip - you'll
> > > be spinning one wheel an awful lot . . .
> > >
> > >
> > > =====
> > > Mark Peele
> >
> >
> >
> > --
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> >
> >

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