Date: Thu, 14 May 2020 17:34:50 -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: <MN2PR08MB62393A9529260509C2F14286A0BC0@MN2PR08MB6239.namprd08.prod.outlook.com>
Content-Type: text/plain; charset="UTF-8"
I’ve had a set of Sachs installed on my 86 Westy Syncro in 2011 - with
factory springs. They’ve been good - good ride, not too stiff and still
doing their job 80,000 km or so later on - they replaced the original Boge
shocks. Mostly highway miles.
Bruce
On Thursday, May 14, 2020, 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: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of ddbjorkman@verizon.net
> Sent: Thursday, May 14, 2020 5:26 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Mono Tube vs Twin Tube Shocks (dampers)
>
> I used the T3's for about 7 years before the current rebuild. Great
> performance. Had a UCA bushing start squeaking on 2nd trip around the
> country. Early Rt. 66 has lots of rough stuff. Got the squeak in the
> Black Hills, coming down from Glacier NP. Got it on a lift, gave it a
> squirt of lube and drove it home to MA and for a couple of months after
> before having to change it out.
> BTW, Thanks for that Bilstein vs. Fox info. This list is such a great
> place to learn and exchange ideas/experiences.
> Dave B.
>
> -----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).
>
> The front end is in good shape otherwise with T3Techniques sourced
> bushings on several parts. The UCA don't have play.
>
> As per heat comment I made, an excerpt from a GW article on Fox vs
> Bilstein shocks
>
> " --- The Fox shocks we sell will handle severe service for between
> about 5-10 times longer (depending on application) than a Bilstein shock
> before giving up the ghost. This is not due to any quality issue; it is
> purely a design issue. The Fox shocks are designed to carry more oil and
> have more surface area—so they can dissipate heat better than the Bilstein
> shocks we offer. It should be noted that Bilstein also makes super high
> performance, off-road shocks—just not for Vanagons or Eurovans. --- "
>
> So it seems that in part, it may be an application issue on my part.
> i.e. types of road I drive on while on camping trips.
>
> Neil.
>
>
>
> On 5/14/20, ddbjorkman@verizon.net <ddbjorkman@verizon.net> wrote:
>
> > ..... Also, if interested in Bilstein's, GoWesty has them made up
> > especially for Vanagons. Take a look.
> > Dave B.
>
>
> 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. ......
>
> > Given what I've read, it seems that a mono tube design shock .....
> > might shed heat better, .....
>
>
> --
> Neil n
>
> VE7TBN
>
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