Shock mount failure

[timvasqz]

when I weld in a triangle gussett, I first cut out the right angle or
just dont weld to the point. On the redesign David has I would think
the gussets are not top and bottom in line with the shock????
Gussetts off to the side of the line of the force would allow for
some distortion in place of total metal failure.

When you beef one thing up the next weak link becomes evident. first
thing I do when I crack an arm on a bobcat is realize the proven
limit then weld it back to spec. I just think the problem is not in
the ride dynamic.

"You can jack a bus up.... by jacking a bus up"
Greg of Tim&Greg
94ptca

--- In WanderlodgeForum@yahoogroups.com, david brady
wrote:
>
> On my street side mount, the gussets coming off the stud are much
> larger and fan out to a much greater area. Plus its orientation is
> reversed from the WB's with the 2 gussets at the top at 10:00 and
> 2:00 and one at the bottom at 6:00, and there's a bolt between
> each gusset. The metal also appears to be thicker, but this is
> difficult to tell thru a photograph. You may consider moving over to
> the LXi style. I have 97,000 miles so far with no trouble. My
> curbside is totally different from the picture that Don took.
>
> David Brady
> '02 LXi, NC
>
> David Brady wrote:
> >
> > You might try looking at the curb side shock mount for ideas. That
> > shock mount appears to be trouble free. Earlier Don took a picture
> > of it. There appeared to be a rectangular cross section tube
welded
> > vertically to it. Something like that or a vertically placed
angle iron
> > might do the trick. I know what you mean though, any fix is simply
> > moving the center of stress around, and possible causing stress
> > raisers elsewhere, that's why looking at the curb side might be
> > informative.
> >
> > David Brady
> > '02 LXi, NC
> >
> >
> > -----Original Message-----
> > From: Leroy Eckert
> > Sent: Feb 19, 2009 7:15 PM
> > To: WanderlodgeForum@yahoogroups.com
> > Subject: Re: [WanderlodgeForum] Re: Shock mount failure
> >
> > Yes, I understand Don. There is a plate there and water can
get
> > behind it. I really do not know how to evaluate that. I
looked at
> > it closely and think a doubler plate could be placed there
with
> > through bolts which might create a weak point at the shock
mount
> > pod weld..Gotta think about that. That is tentative of
course, it
> > was cold and windy today so I did not spend much time
looking. I
> > will look again when it warms again. I have done those types
of
> > mods on aircraft with rivets and it works well.
> > Leroy Eckert
> > 1990 WB-40 Smoke N Mirrors
> > Dahlonega, GA
> >
> > --- On *Thu, 2/19/09, Don Bradner //*
> > wrote:
> >
> > From: Don Bradner
> > Subject: Re: [WanderlodgeForum] Re: Shock mount failure
> > To: WanderlodgeForum@yahoogroups.com
> > Date: Thursday, February 19, 2009, 7:01 PM
> >
> > I'm at around 131,000. There is not a lot of rust except
on
> > the break itself. One thing to not about that rust is
that it
> > was driven in rain the day it broke, and it sat through 10
> > straight days of rain and high humidity after being parked
> > before I looked at it. No way of knowing what the break
looked
> > like at the point it actually gave way.
> >
> > On 2/19/2009 at 3:15 PM Leroy Eckert wrote:
> >
> > >117,000. Fortunately, my coach does not have any
evidence of
> > significant
> > >rust anywhere, even on the chassis. The area around the
shock
> > mount is
> > >clean and black. There is some minor surface rust on the
> > steering rods,
> > >but extremely minor. Virtually nothing on the axle's
front or
> > rear. It is
> > >really clean. That is what I paid for when I purchased
the
> > coach. The
> > >engine has about 25,000 on an in frame. I re-sprayed the
> > insulation on the
> > >bottom of the coach with undercoating. It is shiny and
clean.
> > >Leroy Eckert
> > >1990 WB-40 Smoke N Mirrors
> > > Dahlonega, GA
> > >Royale Conversion
> > >
> > >--- On Thu, 2/19/09, david brady > > > wrote:
> > >From: david brady > > >
> > >Subject: Re: [WanderlodgeForum] Re: Shock mount failure
> > >To: WanderlodgeForum@ yahoogroups. com
> >
> > >Date: Thursday, February 19, 2009, 4:26 PM
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >Leroy,
> > >
> > >
> > >
> > >How many miles on your coach?
> > >
> > >
> > >
> > >David
> > >
> > >'02 LXi, NC
> > >
> > >
> > >
> > >Leroy Eckert wrote:
> > >
> > >
> > >
> > >
> > >
> > >
> > > Thanks for the info. I checked mine out today and it
> > >looks solid.
> > >
> > >Leroy Eckert
> > >
> > >1990 WB-40 Smoke N Mirrors
> > >
> > >Dahlonega, GA
> > >
> > >Royale Conversion
> > >
> > >
> > >
> > >--- On Thu, 2/19/09, Pete Masterson
> > >wrote:
> > >
> > > From:
> > >Pete Masterson
> > >
> > >Subject: Re: [WanderlodgeForum] Re: Shock mount failure
> > >
> > >To: WanderlodgeForum@ yahoogroups. com
> > >
> > >Date: Thursday, February 19, 2009, 1:11 PM
> > >
> > >
> > >
> > >
> > >
> > > I'm inclined to agree that the left shock mount was a
less
> > >robust component than is ideal, possibly due to a
Ridewell
> > error or
> > >miscalculation of stresses. The tear starts at the top
and
> > works down.
> > >That suggests that the force causing the stress is the
fully
> > extended
> > >shock absorber. This is in the opposite direction of
stress
> > caused by
> > >lowering the jacks when the air bags are deflated.
Indeed, in
> > that
> > >situation, the bumper stops ought to be taking the brunt
of
> > the weight
> > >rather than the shock mount, if the shock is of the
correct
> > length.
> > >
> > >
> > >
> > > I noticed the 'popping' noise (that apparently was
> > >indicative of impending failure) whenever I traversed
dips or
> > >undulations in the road. Unfortunately, many freeways and
> > highways in
> > >the SF Bay are built on fill or unstable clay soils, and
> > undulations
> > >caused by ground subsidence is common and occurs
frequently.
> > Even a
> > >small bobble, crossed at 50 or 60+ mph results in a
rather
> > >severe porpoising incident. With the frequency of these
> > undulations in
> > >the area with the heavy, fast moving traffic, it is
rarely
> > possible to
> > >spot the undulation and take protective action before
you're
> > upon it.
> > >(It's so perverse, that one lane may be affected while
other
> > lanes are
> > >not.) Indeed, there have been several studies (over the
> > years) that
> > >suggest that the condition of Bay Area highways may be
> > costing drivers
> > >$billions each year in additional repairs to their
vehicles.
> > Naturally,
> > >living in a near-bankrupt state, there is little chance
that
> > there will
> > >ever be significant improvement.
> > >
> > >
> > >
> > > So, my feeling is that the most likely source of stress
> > >comes from super extension of the shock, rather than
> > compressive stress
> > >caused by lowering the jacks before the suspension is
aired
> > up. I note
> > >that the shock can't be longer, since then it would not
be
> > able to
> > >compress sufficiently in the opposite direction. Further,
> > between the
> > >time of the first repair and the second failure, my
coach did
> > not go
> > >through all that many jack raise/lower cycles and I've
rarely
> > lowered
> > >the jacks without sufficient air in the suspension. (I'd
say
> > never,
> > >because I have a 'get ready to go' procedure that I'm
quite
> > careful to
> > >follow -- but I admit the possibility of a distraction or
> > memory lapse
> > >where lowering the jacks without air in the suspension is
> > possible once
> > >in a while.) In contrast, I probably had many porpoising
> > events for
> > >each jack lowering with or without air in the suspension.
> > >
> > >
> > >
> > > I also speculate that the second failure after the first
> > >repair I encountered is due to the particularly large
number of
> > >porpoising events encountered in Bay Area traffic (and
the
> > generally
> > >poor condition of many California freeways). Of course,
if
> > the first
> > >repair were more robust, I may not have had the second
failure. I
> > >further note that it did take a dozen years and more than
> > 125,000 miles
> > >before the fracture was first found. While we should
expect
> > better,
> > >that's quite a few miles on the chassis without a
failure, so
> > one might
> > >conclude that the part is only just short of
being "strong
> > enough."
> > >
> > >
> > >
> > >
> > > Pete Masterson
> > > '95 Blue Bird Wanderlodge WBDA 42 (For Sale)
> > > <http://www.aeonix.
> > >biz/BBforsale. html>
> > > El Sobrante CA
> > > aeonix1@mac. com
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > On Feb 18, 2009, at 7:45 PM, david brady wrote:
> > >
> > >
> > >
> > > Greg,
> > >
> > >
> > >
> > >I don't think the axle tilt puts undo stress on the
shock. If
> > you
> > >
> > >consider the steer axle in fulldroop on one side and
full bump on
> > >
> > >the other. The angle of the axle is roughly 5 deg to the
> > horizon,
> > >
> > >and this turns out to also be the angle of the shock.
> > >
> > >(inverse sine of (8 inches / 96 inches)). The rubber
bushings
> > >
> > >in the shock can easily comply without transferring
> > >
> > >excessive forces to the mounts. I'm sure Ridewell did
this basic
> > >
> > >calculation. If this were the cause then we'd be seeing
similar
> > >
> > >failures on the drive axles. The cause could be shocks
that
> > bottom
> > >
> > >before bump stops (shocks too long), folks retracting
their
> > >
> > >HWH jacks w/o first airing up the suspension, folks
raising the
> > >
> > >front off the ground w/o first dumping air, or simply and
> > inferior
> > >
> > >Ridewell design. After year 2000 or so, I was informed
by
> > >
> > >the engineering staff at Ridewell that all their
suspension
> > systems
> > >
> > >underwent finite element analysis and subsequent
redesign;
> > >
> > >consequently the LXi uses a different shock mount system
than
> > >
> > >the WB's. Could be that Ridewell addressed an inherent
weakness.
> > >
> > >
> > >
> > >David Brady
> > >
> > >'02 LXi, NC
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >timvasqz wrote:
> > >
> > >
> > > I think the crack was there from off-camber HWH jack
> > >parking in the
> > >
> > >past. looks like the temper of the weld proved a brittle
spot
> > that
> > >
> > >under normal conditions would not have issue. Then the
new shock
> > >
> > >absorbed more bounce but reacted equally agressive
causing
> > much more
> > >
> > >stress on the mount. I think the mount post shoud have
less
> > strength
> > >
> > >and be a point that can bend at failure. the tripod
gussettes
> > are a
> > >
> > >bad idea.
> > >
> > >
> > >
> > >I think problems arise when the bus air bags are dropped
to be
> > >
> > >leveled but the spot is too off camber. the HWH push one
side up
> > >
> > >and tilt the axle too much. at that point raising the
front is
> > >
> > >effortless and and the 30 foot lever post all the stress
on the
> > >
> > >tucked tire.
> > >
> > >
> > >
> > >If I was to repair that mount I would remove two bolts
and
> > make a
> > >
> > >trapazoid shape cut and replace the plate with a butt
weld
> > then build
> > >
> > >the post mount back no better than before.
> > >
> > >
> > >
> > >If you lose an airline and must drive. there is a screw
set
> > in the
> > >
> > >maxicam to turn off the parking brake. you can then plug
the
> > airline
> > >
> > >and fold it over then tape it.
> > >
> > >Greg ofTim&Greg
> > >
> > >94ptca
> > >
> > >
> > >
> > >...--- In WanderlodgeForum@
> > >yahoogroups. com, "Don Bradner"
> > >
> > > wrote:
> > >
> > >>
> > >
> > >> I'm the latest victim of a driver's side front shock
mount
> > failure.
> > >
> > >It took out the brake line when it went. I was not far
from
> > home on
> > >
> > >the way back from Q, so I limped on in (I know, in
retrospect
> > it was
> > >
> > >too dangerous, but I kept a lonnnng following distance!)
> > >
> > >>
> > >
> > >> I've used the local Detroit dealer in Arcata (Trinity
> > Diesel) a
> > >
> > >couple of times now for service, so I called them, and
the
> > service
> > >
> > >manager said he would swing by for a look, no charge. He
> > ended up
> > >
> > >removing the shock and the air line, and said that he
would
> > come by
> > >
> > >the next time he was this way with a new airline. A new
shock
> > will
> > >
> > >have to be ordered (the top bent/caved in) and they will
> > schedule an
> > >
> > >appointment to get it welded after they have that. Shock
was 17
> > >
> > >months old.
> > >
> > >>
> > >
> > >>
> > >
> > >> Don Bradner
> > >
> > >> 90 PT40 "Blue Thunder"
> > >
> > >> My location: www. bbirdmaps.
> > >com/user2. cfm?user= 1
> > >
> > >>
> > >
> > >
> > >
> > >
> > >
> > > No virus found in this incoming message.
> > >Checked by AVG.
> > >Version: 7.5.552 / Virus Database: 270.10.23/1952 -
Release Date:
> > >2/13/2009 6:29 PM
> > >
> > >
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> > >
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> > >
> > >
> > >
> > >No virus found in this incoming message.
> > >Checked by AVG.
> > >Version: 7.5.552 / Virus Database: 270.10.23/1952 -
Release Date:
> > >2/13/2009 6:29 PM
> >
> >
> >
> > ------------------------------------------------------------------
------
> >
> > No virus found in this incoming message.
> > Checked by AVG.
> > Version: 7.5.552 / Virus Database: 270.10.23/1952 - Release Date:
2/13/2009 6:29 PM
> >
>