Date: Sat, 18 May 2002 22:05:30 -0700
Reply-To: John Clemens <jbclem@EARTHLINK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Clemens <jbclem@EARTHLINK.NET>
Subject: Re: anti-sway bar (longish)
Content-Type: text/plain; charset="iso-8859-1"
Andrew,
Interesting story about your Audi 80. I'm not using my 1983 Westphalia for
offroad use in the sense of roads with many levels, but I drive through a
creek everyday and down a dirt road, and until this month I had a Weddle
LockRite always-on locked differential in my 2WD trans. It was great for
driving through the flooding creek at a slow speed(to keep the water splash
from shutting off the waterboxer engine) with confidence that I wasn't going
to get stuck halfway across. Same going through mud holes, I could drive
slow enough to keep the rear from slipping from side to side. Driving on
the highway was a bit annoying because it would veer to the right a little
everytime I shifted, and also clunk, and sounded like I had a bad CV joint
where ever I made a sharp turn or drove in a circle(there had to be a
certain amount of extra play in the differential mechanism to make it work).
The controlable locking differential will be a nice contrast, and may also
make my highway driving more efficient, gas milleage wise. Having a rear
sway bar would make cornering, especially on the canyon roads where I live,
much nicer and the driver wouldn't have to lean as much on the corners.
This rear swaybar discussion also reminds me of my months spend in New
Zealand, with an older type bus(1966), driving across reefs at low tide to
get to way out surfing beaches. Most of the times I got stuck on the
reef(with the tide coming in rapidly, of course) the reason would be that
one of the rear wheels was suspended over a depression in the reef and
therefore just spinning. The solution was to find some extra bodies to
stand on the rear bumper trying to weight that wheel down enough to touch
the rocks piled in the hole and gain traction. Imagine doing that with a
rear sway bar on the car, quite a much more difficult task, eh!
I have lots of stories about driving in impossible places with that VW bus,
in New Zealand, but the main point is that by having the engine weight over
the rear tires I could go places where only Land Rovers were going. I could
never figure out why VW moved the engine up front for the Eurovan.
Thanks for the infomation,
John
----- Original Message -----
From: "Andrew Jack" <andrewxp@AJ.DNSALIAS.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, May 18, 2002 7:40 AM
Subject: Re: anti-sway bar (longish)
> John,
>
> A diff lock goes a long way to eliminating the shortcomings of a sway bar
> off road. Basically, by locking the diff you will still have traction
even
> if one rear wheel is unloaded or in the air. As mentioned by Dave
> Carpenter, the sway bar does not limit *total* wheel travel, just
> independent travel. You could still come unstuck (literally) if the
surface
> is slippery and two driven wheels would give you progress, but one is
> insufficient.
>
> Robert Keezer's example was good, but did not cover the case where there
may
> be changing levels on the road, and for example the left front and right
> rear wheels are up, and the right front and left rear wheels are down.
With
> limited articulation, this can result (if stopped) in the vehicle
> see-sawing or pivoting on a line left front/right rear. A sway bar will
see
> this happening earlier, which was my originial point. Even a four wheel
> drive (without difflocks) will be stuck. Your diff lock would save the
day,
> with the proviso, as stated above, that one driven wheel can provide
enough
> traction to extricate the vehicle.
>
> As for when the diff lock should be engaged, IMHO only when traction loss
is
> imminent and at the lowest practicable speed. In most cases, except when
> very slippery, the diff lock can be engaged once you become "hung up" and
it
> will save the day - this method also has the advantage of the vehicle
> letting you know "I'm almost at the limit". My Audi 80 quattro has a
> pushbutton diff lock that automatically disengages when the speed rises
> above 15mph. A diff lock has the effect of trying to make the vehicle go
in
> a straight line if both wheels on the locked axle have traction - ie loss
of
> steering effectiveness. This is even more pronounced with a front diff
> lock. If the diff lock is engaged on a high traction surface, axle
torquing
> could cause something to break (probably the most expensive component).
>
> As an example of how a diff lock can be used, a couple years back I was at
a
> ski resort, and we had a decent (for Australia) dump of snow (10-12"
IIRC).
> The access roads and main carpark were duly plowed, but not the carpark I
> was in (along with several full size 4WDs and a few 2WDs). We needed to
> reposition the vehicles to fit a few more in, and the 4WDs manouvered with
> much wheelspin, sideslip, snow flying everywhere, foul language and
general
> lack of control. The 2WDers witnessed this and stayed put. I decided,
ok,
> I'll get out of the carpark and let the other guy in (Honda Accord, with
> chains), then bring my car (Audi 80 quattro, no chains) back after he's
> finished fooling around. So, without any fuss, I proceeded to exit the
> carpark. On a steepish slope I engaged the diff lock as there was
(slight)
> side slippage. The Honda then couldn't even make it 10' into the carpark,
> despite chains, lots of run ups and cussing. I then proceeded back into
the
> carpark, again no fuss thanks to the diff lock (& AWD) and parked where I
> had been before. A crowd of onlookers, who had been there from the start,
> was totally amazed by how in control and effortless my maneuvering was
> compared to the 4WDs (messy) and the chained 2WDs (ineffectual) and
several
> looked at my front wheels and said "how did you do that without chains and
> in an ordinary car?".
>
> In regards to articulation, in this context, I was refering to each wheels
> ability to "touch(ing) the ground at the same time", but more specifically
> relative wheel travel - ie a sway bar reduces articulation - or relative
> wheel travel - between the linked wheels.
>
> Andrew
>
> ----- Original Message -----
> From: "John Clemens" <jbclem@earthlink.net>
> To: "Andrew Jack" <andrewxp@AJ.DNSALIAS.NET>; <vanagon@GERRY.VANAGON.COM>
> Sent: Saturday, May 18, 2002 9:09 AM
> Subject: Re: Re: anti-sway bar
>
>
> > Andrew,
> >
> > I'm just seeing this thread and your answer brings a few questions to
> mind:
> > I have an 2 WD '83 Westphalia watercooled with a transmission converted
> to
> > have a vacuum operated locking differential(from a Syncro). How do you
> > think it would work on bad roads with a rear sway bar and the diff lock
> on.
> > How about on the highway? By wheel articulation do you mean the fact
that
> > all wheels are touching the ground at the same time?
> >
> > John
> >
> >
> > ----- Original Message -----
> > From: "Andrew Jack" <andrewxp@AJ.DNSALIAS.NET>
> > To: <vanagon@GERRY.VANAGON.COM>
> > Sent: Friday, May 17, 2002 1:47 AM
> > Subject: Re: anti-sway bar
> >
> >
> > > ----- Original Message -----
> > > From: "Robert Keezer" <warmerwagen@HOTMAIL.COM>
> > >
> > > >I think that you can only gain by adding a anti-sway bar.
> > >
> > > Except if wheel articulation is important to you. Probably more of an
> > issue
> > > in a Syncro, but if you are trying to drive a 2WD on rough tracks this
> > just
> > > puts you further behind the (all wheel drive) eight ball.
> > >
> > > As usual, it's a compromise. I would rather put up with the
rock'n'roll
> > > (and drive accordingly) on road, and know that I have full wheel
travel
> > when
> > > in semi off-road conditions.
> > >
> > > Andrew Jack
> > > Australia
> > >
> > > '92 T3 Syncro
> > >
> >
> >
>
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