Re: Ride heighth adjustment

[James Exler]

'





Mark,

Think of the suspension as a 4 legged stool. Under normal loading, all 4 legs are equally loaded.

If we simulate a sagging spring by cutting an inch off one leg, what happens? As that leg lowers to the floor, the diagonal formed by the two adjacent legs becomes a fulcrum or pivot and the leg diagonally opposite the shortened one rises off the floor.
We have changed the loading.


The suspension acts similar to this. In racing, a spring adjustment on one corner affects the diagonally opposite position, just ask Bill E.

Jim Exler

On 8/8/2019 10:42 AM, Mark Cushman chvet73@... [Safarifriends] wrote:

 


One thing that happened with my Safari is that I had pull to the right when applying brakes.  Once the ride height was corrected that pulling disappeared.  So it clearly effects steering geometry.  


Mark
1999 Safari 32’



Sent from my iPad

On Aug 8, 2019, at 9:13 AM, James Exler jimxexler@... [Safarifriends] wrote:



 




Robert,

There are a few reasons to set the ride height to the factory spec.

First, the drive line angles were set using the right height. As the springs sag, it changes these angles.

Second, the auxiliary suspension components such as the roll bars and pan hard bars were set for the factory height. A lowered height changes their geometry.

Third, the proper height insures the coach is loading the suspension evenly as designed.

Jim Exler

On 8/8/2019 9:51 AM, robertfury@... [Safarifriends] wrote:

 


Not arguing for arguing sake, but if the spring rate isn’t being changed, why do so many on this forum claim it is very important to have the height correct? Obviously one would want to bottom out (which mine isn’t). Is there another reasoning?

Virus-free.
www.avg.com












'

[James Exler]

'





Robert,

The adjustment at the anchor point of a metal torsion bar is merely setting the height of the loaded end when it is loaded as designed. It has nothing to do with the spring value of the bar.


Jim Exler

On 8/8/2019 10:27 AM, robertfury@... [Safarifriends] wrote:

 


So the sagging springs (torsion tube) just wears out? Most trucks today that use torsion springs (just round metal) are adjustable in preload, which raises the heighth. Seems like a bad design. I guess they had their reasoning? Or was it just to save money
over a air bag system? Or air bags weren’t popular then?

Virus-free.
www.avg.com






'

[TD]

'Robert,

This torsion spring suspension is actually a very good, simple and
durable design. It was widely used, and maybe still is used on buses
in Mexico with great success. These torsion springs are know to easily
handle in excess of 1 million miles without issues and needing
repairs.
That said, some of the issues with these suspensions on Safari
coaches, is Safari did a poor job on how they installed and set up
theses suspension. This necessitated things like the radius rods and
panhard rods (Tiger Traks). For an example, on the older Foretravel
Coaches that had the BF Goodrich torsional suspension, there were no
issues, because they did a good job executing the installation.
Another is was, as Safari added more weight to these couches, which
were mostly the later model years, they did not upgrade the capacity
of the springs, at least not on all of the newer coaches. So some of
those models had problems. The older models are pretty much zero
failure rate to this day. The older models with the Oshkosh chassis
were the lightest, so some of those coaches have never needed any
height adjustment at all, and these coaches are in excess of 25 years
old.

Another thing to note on the older models, well, at least on my '95.
The center line of the suspension travel is not at the standard 25''
of ride height, it is more like 24.25 or 24.5 inches, I forget the
number when I had it last measured. My only guess for this
discrepancy, is '94 and '95 model years were the first two years for
the in house Magnum chassis, and they were literally learning as they
went along. Some of the visible differences are, the '96 and newer
units have the propane tank in the front, and the fuel tank and water
tank are placed a bit differently too. On the older models, the
propane tank is in the rear. With the different setups, even the the
Front Tiger Trak bars are different between the '96 and new coaches
and the '94/'95 models years.

Before you do a ride height adjustment on your '94 Safari (I don't
remember your model), with the shocks disconnected, measure your
suspension travel, split the difference, raise your coach up to that
center point you measured at, and then measure your ride height. This
will tell you where the suspension center point is, using the ride
height measurements. This is the likely reason why your coach does not
bottom out, even though it may be bellow the 25 inch spec.
To make this even more odd for us older coach owners, the rear
suspension center point is 25 inches, just like the rest of the
coaches.

One last note, I don't know how it is for other coaches, but on my
coach, even with the correct ride height, the drive shaft angle are
horrible, and short of remounting the engine mounts, there is nothing
you can do about it.

John
'95 Safari Serengeti 38ft, Cummins C8.3-300, Allison
6spd

On 8/8/19, robertfury@... [Safarifriends]
wrote:

> So the sagging springs (torsion tube) just wears out? Most trucks today
> that use torsion springs (just round metal) are adjustable in preload, which
> raises the heighth. Seems like a bad design. I guess they had their
> reasoning? Or was it just to save money over a air bag system? Or air bags
> weren’t popular then?
>
> ------------------------------------
> Posted by: robertfury@...
> ------------------------------------
>
> Community email addresses:
> Post message: Safarifriends@onelist.com
> Subscribe: Safarifriends-subscribe@onelist.com
> Unsubscribe: Safarifriends-unsubscribe@onelist.com
> List owner: Safarifriends-owner@onelist.com
>
> Shortcut URL to this page:
> http://www.onelist.com/community/Safarifriends
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

'

[robertfury@gmail.com]

'Certainly compressing a spring, while not changing the spring itself, changes how it performs, whether it be a torsion or a coil spring.

Thanks for all the info! I just was under my coach, tinkering, moving things with a lever, and I thought the spring rate seemed soft. My coach only has 42k miles, so it can’t be much from wear. Maybe that’s just the way it was designed. After I get the new shocks on I will evaluate the ride.

94 Continental'

[TD]

'Robert,

You are absolutely correct, but as Jim explaned, whether it is a steel
or rubber torsion spring, adjusting ride hight will not compress
either style of spring. It is the load you put on the spring, by
loading it. Hence, coach and cargo weight. On some vehicle with steel
torsion springs, one could, in theory, over-tighten the spring to the
point that the suspension is loaded beyond the extended suspension
travel, tightening that spring beyond that travel will begin to load
it, but these circumstances are not realistic and would be improper
procedure. On our coaches it is physically IMPOSSIBLE to load the
spring by adjusting ride height. As Jim explained very well, it is the
weight you put on the spring that loads it, raising the coach height
does not and will not add weight in of itself. It is plain physics and
geometry...

As for your torsion springs, they are supposed to be soft for a good
quality ride. If the inner tube is centered inside the square tube,
and your shackles are not cocked/lopsided/out of alignment, then it is
very likely that there is nothing wrong with your springs.

If you want, post pictures of your springs and shackles in question,
so we could take a look at the condition and how well it is
centered/aligned. Also please post your ride height at all for tires,
measured on level ground.

John
'95 Safari Serengeti 38ft, Cummins C8.3-300, Allison
6spd

On 8/8/19, robertfury@... [Safarifriends]
wrote:

> Certainly compressing a spring, while not changing the spring itself,
> changes how it performs, whether it be a torsion or a coil spring.
>
> Thanks for all the info! I just was under my coach, tinkering, moving
> things with a lever, and I thought the spring rate seemed soft. My coach
> only has 42k miles, so it can’t be much from wear. Maybe that’s just the
> way it was designed. After I get the new shocks on I will evaluate the
> ride.
>
> 94 Continental
>
> ------------------------------------
> Posted by: robertfury@...
> ------------------------------------
>
> Community email addresses:
> Post message: Safarifriends@onelist.com
> Subscribe: Safarifriends-subscribe@onelist.com
> Unsubscribe: Safarifriends-unsubscribe@onelist.com
> List owner: Safarifriends-owner@onelist.com
>
> Shortcut URL to this page:
> http://www.onelist.com/community/Safarifriends
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

'

[robertfury@gmail.com]

'TD, thank you for the info. I can see how in this case it makes no difference, as you aren’t adjusting the torsion tube to adjust ride heighth. I’m hoping my new shocks make all the difference. I received the Evo Koni’s, but 1) had a problem getting one old shock off 2) tried putting one new one on without greasing or de rusting the shaft it goes onto and it is stuck but not seated. Ordered a puller for both problems. Sometimes I make the dumbest mistakes.

Thanks again! I think I’m going to leave the suspension right where shes as at for now, especially since I’m not on level ground and don’t want to move. Maybe when I’m in Mexico this winter, tired of sipping margaritas and surfing, I will tackle this.'

[TD]

'Robert,

Mexico sounds like it will be a blast, and lower cost of living to
boot. A win win.

As for your ride/shocks, remind me, what are the issues you are having
with your ride quality. Harsh ride, porpoising???

Try using PB Blaster and a rubber mallet, with some finagling you
should be able to get it back off. Before greasing and reinstalling, I
would sand down or file the rust off.

The shocks you removed, were the Bilstein? If yes, they are probably
original and were really rusted on good.

John
'95 Safari Serengeti 38ft, Cummins C8.3-300, Allison
6spd

On 8/8/19, robertfury@... [Safarifriends]
wrote:

> TD, thank you for the info. I can see how in this case it makes no
> difference, as you aren’t adjusting the torsion tube to adjust ride heighth.
> I’m hoping my new shocks make all the difference. I received the Evo
> Koni’s, but 1) had a problem getting one old shock off 2) tried putting one
> new one on without greasing or de rusting the shaft it goes onto and it is
> stuck but not seated. Ordered a puller for both problems. Sometimes I make
> the dumbest mistakes.
>
> Thanks again! I think I’m going to leave the suspension right where shes as
> at for now, especially since I’m not on level ground and don’t want to move.
> Maybe when I’m in Mexico this winter, tired of sipping margaritas and
> surfing, I will tackle this.
>
> ------------------------------------
> Posted by: robertfury@...
> ------------------------------------
>
> Community email addresses:
> Post message: Safarifriends@onelist.com
> Subscribe: Safarifriends-subscribe@onelist.com
> Unsubscribe: Safarifriends-unsubscribe@onelist.com
> List owner: Safarifriends-owner@onelist.com
>
> Shortcut URL to this page:
> http://www.onelist.com/community/Safarifriends
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

'

[robertfury@gmail.com]

'I did the PB blaster to no avail. I spend a month ON the ocean in Texas, I suspect this is the problem. They are actually some semi truck shocks I bought to SAVE money. Replaced the original Koni’s. As it turns out the originals might not have even been worn out, but lesson learned. Extreme porpoising, which tells me there isn’t enough dampening. Also some wander, but I’ve gotten used to that, and it’s not really all that bad. Steering rack is tight, tires good, maybe alignment, I doubt one has ever been done since I bought it with 35k miles. So porpoising and side to side back and forth pitching when going over curbs/uneven surfaces.

Very excited about Mexico. That’s why I’ve been posting so much here lately. I did a complete interior remodel when I bought the coach, also redid the roof, but didn’t attend to the mechanical as much. Now that I’ve driven it 7k miles I know the problems that I want to fix. If you’ve ever been to Baja, you know the roads can go from super smooth to terribly pot holed in an instant. So even though a good ride won’t help on the worst of roads, it will make it a safer more enjoyable coach to drive on the rest.'

[robertfury@gmail.com]

'Bill, these Tiger Traks, are they still sold by the manufacturer? Do they replace the original sway bar? Or work in addition? Are they something an enthusiastic novice to experienced amateur (With good instructions I can complete most things) can put on himself? Price range?

Looked at the torque tubes today. The metal shaft is centered. Rubber is a little cracked/dried out on surface, but looks in good nick mostly and adhered correctly, linkages all look in line to each other, not wracked.'