What is the reason for the left front shock mount failures on 90's buses?

[Eric Perplies]

Yes, Don the right side is much better re-enforced than the left side.

I wonder if that means that the cause of our failures has been an inadequately
strong parent metal frame: the Ridewell frame?? I suppose if this portion of
the coach is adequately strong it may not fail. I have a lurking thought in the
back of my mind that making the frame adequately strong might both prevent that
part from breaking again and it might keep the real problem from doing it's
damage.

The obvious potential problem is that when we bottom out the front suspension
perhaps we bottom out the shock and really put a stress on the frame. The
problem with this hypothesis is that there are suppose to be stops in the
suspension that are intended to keep this from happening. As Dave mentioned
previously the system is suppose to be able to withstand a tremendous force.
I've not approached any shock to my system that would the limits that Dave
mentioned but of course the dynamics of a pot hole strike can be pretty severe.

I don't have the resources to evaluate whether the suspension travel stops are
adequate to keep the shock from bottoming out. It would take CAD modeling or
some testing without the Koni shocks on. The measurements I made of the Koni's
is collapsed length of 13 1/4". An extended length of 19 3/4" which means there
is an overall travel length of 6 1/2", as I measured it.

The reason for the failure that makes the most sense to me is that the frame is
bottoming out and either the stops or the suspension are flexing causing the
shock to bottom out. The pictures of some of the other failures suggest the
break may have started at the bottom of the break, rather than the top.

If I could get real skinny and get under my coach when I air it down, I wonder
if the stops would be touching or whether the load would be bore by the shock
absorber. Perhaps if I could measure the center distance between the shocks it
would tell the story. I really need to go on a diet to hope to do this test.

Eric Perplies
96' 42' WBWL

[timvasqz]

just remove the shock and jack up the axle to measure the close distance from
center of shockA pins. if the closed shock is greater distance, the mystery is
solved.

Cracks are like blown fuses, always a result. Attention to replacement/repair
of a result is a tempoary fix.

Greg ofTim&Greg
94ptca


--- In WanderlodgeForum@yahoogroups.com, "Eric Perplies" wrote:
>
> Yes, Don the right side is much better re-enforced than the left side.
>
> I wonder if that means that the cause of our failures has been an inadequately
strong parent metal frame: the Ridewell frame?? I suppose if this portion of
the coach is adequately strong it may not fail. I have a lurking thought in the
back of my mind that making the frame adequately strong might both prevent that
part from breaking again and it might keep the real problem from doing it's
damage.
>
> The obvious potential problem is that when we bottom out the front suspension
perhaps we bottom out the shock and really put a stress on the frame. The
problem with this hypothesis is that there are suppose to be stops in the
suspension that are intended to keep this from happening. As Dave mentioned
previously the system is suppose to be able to withstand a tremendous force.
I've not approached any shock to my system that would the limits that Dave
mentioned but of course the dynamics of a pot hole strike can be pretty severe.
>
> I don't have the resources to evaluate whether the suspension travel stops are
adequate to keep the shock from bottoming out. It would take CAD modeling or
some testing without the Koni shocks on. The measurements I made of the Koni's
is collapsed length of 13 1/4". An extended length of 19 3/4" which means there
is an overall travel length of 6 1/2", as I measured it.
>
> The reason for the failure that makes the most sense to me is that the frame
is bottoming out and either the stops or the suspension are flexing causing the
shock to bottom out. The pictures of some of the other failures suggest the
break may have started at the bottom of the break, rather than the top.
>
> If I could get real skinny and get under my coach when I air it down, I wonder
if the stops would be touching or whether the load would be bore by the shock
absorber. Perhaps if I could measure the center distance between the shocks it
would tell the story. I really need to go on a diet to hope to do this test.
>
> Eric Perplies
> 96' 42' WBWL
>