Bouncing Birdie

[gregory O]

The tighter your springs the less rebound weight there is on an axle. If you
limit the bounce of an object the momentum attributed force has less chance to
build. When the front end comes off the ground the max achieved force at
rebound is a weight value. at the bottom of the spring compression you have
actual static weight and the momentum force of the weight in motion.
I test this theory often; I place my 22lb wooden handle sledge hammer on a
customers patio and nothing happens. I then swing the sledge in a 7 foot
radius; when it rest once again on their patio, I write an invoice.

payload in a vehicle that leaves the deck floor on a hard bump adds additional
force when the downward momentum changes direction. shock mounted gensets,
people/live cargo, etc all add to ending force as they build more momentum with
the additional travel distance. My fithwheel/toyhauler friends have learned to
'compress the springs' and 'tie down' their sand toys while in transit. the
first sign of a bounce damaged toyhauler is wrinkled side wall aluminum. Since
the Bluebird side wall wont react to absorb this force all the energy goes to
the axles.

Large commercial truck engineering install equipment like 'cab-shocks' and 'air
ride seats' to keep the drivers teeth in their head. one of the big problems
with the old Mack no spring Dump and Concrete trucks was they would develop
cracks in the metal frame and cab when there was no bounce to handle engine and
road vibration. That is opposite the result of rebound damage when a max loaded
truck bouncy suspension hit a pothole and destroyed an axle.

The Bluebird engineers 'Bird-Brains' had a recent recall with under weight
rated front axles. I cant believe that being that close to a rated weight by
itsself should have any effect on the enduring performance. I think suspension
ride design is another factor to possible failure for consideration. To give a
static weight rating to an axle is a simplistic way for DOT to access legal use.

There is much more that goes into reengineering suspension. would do best to
consider all the variables.

Greg of Tim&Greg
94ptca

--- In WanderlodgeForum@yahoogroups.com, "bumpersbird" wrote:
>
>
>
>
> Thanks guys,
>
> I was going to replace the valves as well as adjusting my tag axle
> pressure down to 60 psi from it's current 72 psi. Steer axle has too
> much weight on it and the tag is too light. My coach has always looked a
> little nose heavy, after checking the prescribed measurements it is nose
> low. Weighed the coach and she is within 180 lbs of max steer axle
> weight and the tag has an extra 1100 lbs to take up some of that weight.
>
>
> Just to make sure I get the correct part.
>
>
> BB 0871376
>
>
> Haladex 90054007
> http://www.haldex.com/en/North-America/A...t-cat\
> egories/Brake--Suspension-Systems/Suspension-Controls/Height-Control-Val\
> ve/CR-Height-Control-Valve/90054007
> <http://www.haldex.com/en/North-America/A...ct-ca\
> tegories/Brake--Suspension-Systems/Suspension-Controls/Height-Control-Va\
> lve/CR-Height-Control-Valve/90054007>
>
>
> Neway 90054007
>
>
> Newstar S-8718
> http://www.sandstruck.com/catalog/airsys...ontrol.htm
> <http://www.sandstruck.com/catalog/airsys...ontrol.htm>
>
>
> Velvac # 034112
> http://www.velvac.com/pdf/HeightControlValves.pdf
> <http://www.velvac.com/pdf/HeightControlValves.pdf>
>
>
> Cross Reference: 439 E4323, 480 SA1560, 655 574696C91, BKS KD2328, S46
> M3263
>
>
> Guys got them on e-bay for $35
> http://cgi.ebay.com/ebaymotors/Neway-Hei...iewIt\
> emQQ_trksidZp3286Q2em20Q2el1116QQhashZitem5182f6337aQQitemZ350089524090Q\
> QptZOtherQ5fVehicleQ5fParts
> <http://cgi.ebay.com/ebaymotors/Neway-Hei...ViewI\
> temQQ_trksidZp3286Q2em20Q2el1116QQhashZitem5182f6337aQQitemZ350089524090\
> QQptZOtherQ5fVehicleQ5fParts>
>
>
> Greg, I don't have to look for problems they find me! LOL
>
> Kurt Horvath
> 95 PT 42
> 10AC
>
> --- In WanderlodgeForum@yahoogroups.com, Ralph Fullenwider
> wrote:
> >
> > Hi Kurt:
> >
> > The symptoms sound like the plastic diverter paddle inside the ride
> height
> > valve broke. When the Coach goes positive it will lose air in the
> front
> > bags when it should be filling because of a hair line crack, then when
> it
> > goes neg it closes the crack and fills to the O-Bal point. This will
> cause
> > some effect of the bouncy feeling as well because the air springs are
> > softer due to lack of air but not totally down. You can remove the
> valve,
> > open it up and check the plastic diverter paddle in side that is
> hooked to
> > the arm, bet you will find it damaged and replace it.
> >
> > Safe travels,
> >
> > Ralph & Charolette Fullenwider
> > '84 FC 35 "Ruff Diamond"
> > Duncan, Oklahoma
> >
> > At 05:41 AM 9/24/2009 +0000, you wrote:
> > >Several weeks ago I made a run to IL from Tn and back. I encountered
> a
> > >problem I've not heard about or experienced.
> > >
> > >On the highway I crossed an overpass with a rather abrupt transition.
> The
> > >coach hit hard and my drivers chair bottomed out. Not to unusual. But
> this
> > >time the suspension warning light & alarm came on. I pulled over as
> soon
> > >as I could to check out the problem. Everything appeared normal and
> within
> > >a minuet or so the alarm went out on it's own. I guessed that perhaps
> the
> > >bump had compressed the suspension enough to activate the alarm,
> maybe it
> > >was a real big bump.
> > >
> > >It happened several more times that day, with it occurring in know
> > >stretches of interstate, that have never posed any such problems in
> the
> > >past. With it getting progressively worse. Small bumps would get the
> coach
> > >porpoising.
> > >
> > >Stopped several times, I dumped and aired up the suspension several
> times
> > >to see if it was working and she aired up fine until the next bump in
> the
> > >road . Any ideas???
> > >
> > >I'm thinking it's the air valve for the front suspension. Maybe the
> > >actuator arm is bent, broke or the valve itself is malfunctioning.
> I'm
> > >hoping it's not much more.
> > >
> > >Any help would be great.
> > >__________________
> > >Kurt Horvath
> > >95 PT 42
> > >10AC
> > >
> > >
> >
>