Firestone standoff angle - why?

[larry engelbrecht]

Hello all. Getting ready to cut standoffs for the Firestone 9294 airbags. Looking at the spec sheet and specs of what others have posted, I'm trying
to figure out why the airbag plates shouldn't be parallel at normal ride height: ~13.5" from suspension airbag mount point to point. Is it due to some
weird angle possible during extreme suspension movements? It would make sense to me that somebody had something considered, I just haven't read about
why if that's the case. Can somebody knowledgeable about that chime in? Thank you in advance.

Larry Engelbrecht
C: 858- tree fo non -6472
larryengelbrecht at gee mail dot com
--
Larry Engelbrecht

San Diego, CA

'73 26' ex-Glacier

TZE063V100319 03/07/73

 

[sgltrac]

Larry,

When at ride height the mounting surfaces for the airbag are not parallel.
As the suspension moves the angle changes even more as the rear of the
coach moves upward. The height and angle of the mounts need to be adjusted
for optimal bag alignment on the cone or at least a best case scenario
throughout usual bogie arm rotation.

Sully
Bellevue wa.

On Tue, Jun 9, 2020 at 12:46 PM Larry Engelbrecht via Gmclist <

> Hello all. Getting ready to cut standoffs for the Firestone 9294 airbags.
> Looking at the spec sheet and specs of what others have posted, I'm trying
> to figure out why the airbag plates shouldn't be parallel at normal ride
> height: ~13.5" from suspension airbag mount point to point. Is it due to
> some
> weird angle possible during extreme suspension movements? It would make
> sense to me that somebody had something considered, I just haven't read
> about
> why if that's the case. Can somebody knowledgeable about that chime in?
> Thank you in advance.
>
> Larry Engelbrecht
> C: 858- tree fo non -6472
> larryengelbrecht at gee mail dot com
> --
> Larry Engelbrecht
>
> San Diego, CA
>
> '73 26' ex-Glacier
>
> TZE063V100319 03/07/73
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[larry engelbrecht]

Thank you very much for responding, Todd. I presently have 13 1/2" long 4x4s temporarily holding up the coach. I need to verify ride height and verify
the angle you describe when I take a closer look. At a glance, they appeared to be parallel, but you're likely very correct. I thought it might have
something to do with weird angles causing internal interference or bag tearing issues at the extremes of travels.

Much appreciated.

Larry Engelbrecht
--
Larry Engelbrecht

San Diego, CA

'73 26' ex-Glacier

TZE063V100319 03/07/73

 

[jim kanomata1]

Larry,
You need to follow the specs for rear height. your either too high or to
low.
When the height is correct the plates will be parallel, the way it was
designed..

On Tue, Jun 9, 2020 at 3:55 PM Larry Engelbrecht via Gmclist <

> Thank you very much for responding, Todd. I presently have 13 1/2" long
> 4x4s temporarily holding up the coach. I need to verify ride height and
> verify
> the angle you describe when I take a closer look. At a glance, they
> appeared to be parallel, but you're likely very correct. I thought it might
> have
> something to do with weird angles causing internal interference or bag
> tearing issues at the extremes of travels.
>
> Much appreciated.
>
> Larry Engelbrecht
> --
> Larry Engelbrecht
>
> San Diego, CA
>
> '73 26' ex-Glacier
>
> TZE063V100319 03/07/73
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502

 

[bill wevers]

If you are interested, here is data from my spreadsheet boggie arm angles and ride height.

--
Bill Wevers GMC49ers, GMC Western States
1975 Glenbrook - Manny Powerdrive, OneTon
455 F Block, G heads
San Jose