

| Subject: | Re: Mono Tube vs Twin Tube Shocks (dampers) |
| From: | Bruce Todd |
| Date: | Thu, 14 May 2020 17:34:50 -0700 |
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 > > 1988 Westy 50º ABA swap: https://eur02.safelinks. > protection.outlook.com/?url=https%3A%2F%2Ftinyurl.com% > 2Fyap5hpwt&data=02%7C01%7C%7Ce4613de512a9406f066708d7f84d7a21% > 7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637250883957282088&sdata= > dFHtv2zNPBPfk0Sp8RvJPMg37JmogihhANqvAKVxPw8%3D&reserved=0 > > 1981 Westy 15º ABA swap: https://eur02.safelinks. > protection.outlook.com/?url=https%3A%2F%2Ftinyurl.com% > 2Fy9n4xob8&data=02%7C01%7C%7Ce4613de512a9406f066708d7f84d7a21% > 7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637250883957282088&sdata= > ZntIKRoBKURQRQhp07N8r%2Ff%2FXsc0oTeTgrr5IKjf35I%3D&reserved=0 > > VAG Gas Engine Swap Group <https://eur02.safelinks. > protection.outlook.com/?url=http%3A%2F%2Ftinyurl.com% > 2Fkhalbay&data=02%7C01%7C%7Ce4613de512a9406f066708d7f84d7a21% > 7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637250883957282088&sdata= > 47PmWqHiZAh5tm%2FgH4tBdo3HYpm5QjIsoghr6MT1uTA%3D&reserved=0> >
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