Date: Sat, 16 May 2020 14:42:42 -0700
Reply-To: Bruce Todd <beeceetee@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bruce Todd <beeceetee@GMAIL.COM>
Subject: Re: Mono Tube vs Twin Tube Shocks (dampers)
In-Reply-To: <MN2PR08MB6239A8C712BFC4CBFBA29963A0BD0@MN2PR08MB6239.namprd08.prod.outlook.com>
Content-Type: text/plain; charset="UTF-8"
Back to shocks and springs....I thought I'd make a quick measurement to see
where things were riding on my Syncro Westy - looks like approximately
18.75" from the centre of the axle hub to the fender edge. Not sure if
that is close to stock or not. I thought the Bentley might have some
information - but didn't find anything.
Bruce
On Thu, May 14, 2020 at 7:10 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> Since there can be many variables with tires and wheels the best
> measurement is axle center to fender lip. Up front ~17 inches is the
> reasonable limit. The early suspensions use a different lower control arm
> then the Waterboxers but there is little difference in ride height. Another
> indicator is the angle of the upper control arm. Should be close to
> straight out when loaded.
>
> Dennis
>
>
>
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows 10
>
> From: Neil N<mailto:musomuso@gmail.com>
> Sent: Thursday, May 14, 2020 8:59 PM
> To: Dennis Haynes<mailto:d23haynes57@hotmail.com>
> Cc: vanagon@GERRY.VANAGON.COM<mailto:vanagon@gerry.vanagon.com>
> Subject: Re: Mono Tube vs Twin Tube Shocks (dampers)
>
> Wow. Thanks Dennis. I think I get the gist of what you're saying. I
> now wonder if the Gowesty "zero lift" progressive springs in my '81
> have set the van higher than OE height and if they factor in to what
> may be premature wear on my low mileage Sachs shocks. I have newer
> lower mileage Sachs shocks in my '88, which has seen *some* dirt
> roads, but that bus still has OE springs. And, I don't know if those
> springs have gotten "shorter" due to wear.
>
> In hindsight, the Bilstein HD shocks I installed on my '81 way back in
> 2007 came with spacers that got installed inside the dust boot. I
> guess they might effectively lengthen the shock but maybe it was
> simply a means of adapting a shock that was built for several
> different vehicle applications? The mostly likely factory OE Boge
> shocks that were removed struck me as being a stout looking part and I
> did wonder if replacing them was actually warranted. But I knew much
> less about wrenching at that time.
>
> Personally, my only real concern is finding an affordable or budget
> shock that can handle some off road use.
>
> Gowesty comments in one of their ads that the Bilstein HD is not
> actually a heavy duty shock but maybe thats a marketing ploy to direct
> customers to their XHD Bilstein shocks.
>
> I agree about Fox shock price. I have no plans to buy those. Maybe
> I'll stick with Bilstein HD's and call it done. There are Munroe mono
> tube shocks that looked promising but they're listed for truck
> applications. None listed for the Vanagon.
>
> I will be curious to open up the Sachs I plan to replace on my '81.
> See what failed and what design they are though I suspect they're a
> twin tube design.
>
> Neil.
>
>
> On 5/14/20, Dennis Haynes <d23haynes57@hotmail.com> wrote:
>
> > So I finally have a chance to respond to this thread. So here some Dennis
> > thoughts to ponder.
> >
> > The vanagon in general is not tough on shocks and the original shocks
> were
> > of outstanding design and quality. There are many out there still
> working as
> > they should. Like many things aftermarket you can replace 20 year old,
> 200K
> > mile parts and the replacements are temporary!
> > For Vanagon 2WD front shocks things go downhill very fast. To begin with
> > there is a dual part design dilemma that needs attention. Most all
> > aftermarket shocks are too long. So what's the big deal? Well, let's
> also
> > add that many upper ball joints do not have enough articulation to
> > accommodate the suspension drop when the wheels are unloaded. Add another
> > 1/2" of drop and the upper ball joint doesn’t stand a chance. The pricey
> > Moog joints are now not right either. I just destroyed a pair before it
> even
> > left the lift. GoWesty ball joint spacers to the rescue. Of the Ball
> joint
> > brands out there the Meyle HD is still fitting the best. How did that
> > happen.
> >
> > So back to the shocks. For some reason many of us think stiffer is
> better.
> > Remember the primary purpose of the damper is to control wheel bounce and
> > then vehicle motion. Shock dampening does not stop or eliminate leaning,
> > only the rate at which it happens. Now when you hit a road impact,
> whatever
> > the resistance the shock has to the impact becomes pressure on the
> > hydraulics. Too much pressure and seals get damaged. Now here comes the
> bad
> > part. So on an impact instead of compressing the overly stiff shock now
> > lifts the vehicle. Raise the vehicle high enough and the suspension will
> > drop to the limit before the tire gets back on the ground. Since the
> shock
> > is the suspension travel limiter this damages the top of the shock piston
> > and bottom of the end cap. This extension also stresses the top ball
> joint
> > mentioned earlier.
> >
> > But wait, we have more! Since we didn’t make things difficult enough with
> > parts quality and original design mistakes we also changed the springs to
> > increase ride height. So now instead the shock spending most of its time
> mid
> > travel we reduced the available travel up top so that every time we go
> over
> > a significant bump we test the shock by banging the piston against top
> cap.
> > Also when we extend the shock the steering geometry puts it at an angle
> > relative to the top mount which adds a side load to the piston-rod
> assembly.
> > With the shaft extended the side leverage is high and the shorter
> distance
> > between the piston and cap give the piston and rod little leverage to
> resist
> > this so the piston and top seals get damaged.
> >
> > Over the years I have cut some failed shocks to what happened. I've seen
> the
> > smashed pistons and caps along with the sheared or twisted seals. Even
> > without lifted springs. Could be this is the real reason VW lowered the
> > suspension height for the later years. I remember when VW did one of
> those
> > service bulletins to replace the upper ball joint bolts. Yes they used
> to be
> > hex heads. And they would come loose or break.
> >
> > So for shock selection in my mind the Fox shocks are just too pricey. The
> > Bilsteins are my usual first choice and while I don’t think the GW HD are
> > needed just because you have a camper, I think the increased rebound
> damping
> > for the front may avoid or at least reduce some of the damage mentioned
> > above. My 91 destroyed a set of Bilstein fronts and now needs upper ball
> > joints. This is running the Syncro org springs and last year I put on the
> > 235/55-17 tires/wheels. I will be adding the ball joint spacers when I
> > replace the joints. I have also had good results with Gabriel shocks for
> > economy fitments. The Monroe, not so much. The Sachs, Boge, B4 Bilsteins
> > also work well with stock springs.
> >
> > Dennis
> >
> >
>
> > -----Original Message-----
> > From: Neil N <musomuso@gmail.com>
> > To: ddbjorkman@verizon.net <ddbjorkman@verizon.net>
> > Cc: vanagon@gerry.vanagon.com <vanagon@gerry.vanagon.com>
> > Sent: Thu, May 14, 2020 12:27 pm
> > Subject: Re: Mono Tube vs Twin Tube Shocks (dampers)
>
>
> > Thanks. Yes I recall something about GW developing a shock possibly one
> > better suited to their progressive springs (as I have).
> >
>
> >
> > On 5/13/20, Neil N <musomuso@gmail.com> wrote:
> >
> >
> >> My Sachs OE type shocks don't seem to hold up for very long given that
> >> I drive on bumpy dirt roads at times. ......
>
> >
>
>
> --
> Neil n
>
> VE7TBN
>
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>
> 1981 Westy 15º ABA swap:
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>
> VAG Gas Engine Swap Group <
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>
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