Front end sag after one-ton install?

[Jim Hupy]

Brian, I see 'em.
Jim Hupy
Salem, Oregon

On Sat, Apr 11, 2020, 1:27 PM Brian Waddell via Gmclist <

> test...anybody read this test..I am reading posts but I get no response
> from my inquiries
>
> ________________________________
> From: Gmclist on behalf of Bruce Hislop
> via Gmclist
> Sent: April 11, 2020 6:42 AM
> To: gmclist
> Cc: Bruce Hislop
> Subject: Re: [GMCnet] Front end sag after one-ton install?
>
> Here is a posting in the Photosite where someone (voodooling) used an
> impact wrench socket to adapt the lower control arm to accept the newer,
> shorter
> torsion bars.
>
> I'm sure there was another guy that did this as well.
>
> Has anyone else done this mod?
>
> BTW, who is voodooling?
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
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>

 

[Ken H.]

Brian,
This is the first post I've seen from you in this thread. Are you using
the Forum or email?

Ken H.

On Sat, Apr 11, 2020 at 4:27 PM Brian Waddell via Gmclist <

> test...anybody read this test..I am reading posts but I get no response
> from my inquiries
>
> ________________________________
> From: Gmclist on behalf of Bruce Hislop
> via Gmclist
> Sent: April 11, 2020 6:42 AM
> To: gmclist
> Cc: Bruce Hislop
> Subject: Re: [GMCnet] Front end sag after one-ton install?
>
> Here is a posting in the Photosite where someone (voodooling) used an
> impact wrench socket to adapt the lower control arm to accept the newer,
> shorter
> torsion bars.
>
> I'm sure there was another guy that did this as well.
>
> Has anyone else done this mod?
>
> BTW, who is voodooling?
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Joe Weir]

Hi Brian.

I can see your posts.

This board runs a little slower than social media, especially around the Holidays.

Welcome to GMC Net.

> test...anybody read this test..I am reading posts but I get no response from my inquiries
>
> ________________________________
> From: Gmclist on behalf of Bruce Hislop via Gmclist
> Sent: April 11, 2020 6:42 AM
> To: gmclist
> Cc: Bruce Hislop
> Subject: Re: [GMCnet] Front end sag after one-ton install?
>
> Here is a posting in the Photosite where someone (voodooling) used an impact wrench socket to adapt the lower control arm to accept the newer,
> shorter
> torsion bars.
>
> I'm sure there was another guy that did this as well.
>
> Has anyone else done this mod?
>
> BTW, who is voodooling?
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

--
76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator, brakes, Sully airbags, fuel lines, seats, adult beverage center... those Coachmen
guys were really thinking about us second hand owners by including that beverage center...
Columbia, SC.

 

[Joe Weir]

Regarding adapters, I could have swore I read a thread recently that opined that if length is the issue, the torsion bar crossmember could be moved
forward on the frame rails - taking up the difference.

Does that thread exist?
--
76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator, brakes, Sully airbags, fuel lines, seats, adult beverage center... those Coachmen
guys were really thinking about us second hand owners by including that beverage center...
Columbia, SC.

 

[Ken H.]

Joe,

That's true. This may or may not be the thread you're looking for, but it
should answer most of your questions:

http://www.gmcmhphotos.com/photos/g5973-torsion-bars-and-pork-chops.html

While getting that URL, I notice this album which may be of interest to
some while TB's are of interest:

http://www.gmcmhphotos.com/photos/g5964-pork-chop-measurement.html

Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, Troy-Bilt APU, etc., etc., etc.
www.gmcwipersetc.com

On Mon, Apr 13, 2020 at 10:35 AM Joe Weir via Gmclist <

> Regarding adapters, I could have swore I read a thread recently that
> opined that if length is the issue, the torsion bar crossmember could be
> moved
> forward on the frame rails - taking up the difference.
>
> Does that thread exist?
> --
> 76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator,
> brakes, Sully airbags, fuel lines, seats, adult beverage center... those
> Coachmen
> guys were really thinking about us second hand owners by including that
> beverage center...
> Columbia, SC.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Joe Weir]

For one set, it would be pricey. Could that part not be forged with the socket? With enough quantity, the price might be not horrendous.

> ...The other option is to machine the adapter out of solid 4340 annealed bar stock and then just have it heat treated, no welding. But machining
> that deep female hex is no easy chore...
>
>
> Thanks!
>
> Robert

--
76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator, brakes, Sully airbags, fuel lines, seats, adult beverage center... those Coachmen
guys were really thinking about us second hand owners by including that beverage center...
Columbia, SC.

 

[Matt Colie]

Robert,

Welcome to the group, family, cult, asylum....

As good as FB is at collecting people, I always warn others of the level of expertise that is there. I have seen two salvageable coaches go to scrap
(well, one exchanged for the price of the tow) because owners took the bad advice that they were given.

Now, because you are here and an owner, you are now part of an amazing community. It is like very few other. Everybody here has a not-so-hidden
agenda. That agenda is that you will get to enjoy both the coach itself and what it can do for you. To that end, there is support available here
that you might not expect. The best thing you can do right now is to fill in a sigfile. Go to then select
. Look for the box (I think you found once) to write: Your real name because we like to know who we are helping, a short about the coach
not unlike what you have, and a geographic reference so that someone that is in striking range will know. Yes, you have that in the header, but about
half of the readers get this as e-mail and don't get to see that header.

As said, this is a very supportive and helping community. It is like you just collected about a thousand new old friends you still have to meet. The
other community that I know of that is like this is that of the watermen that are my world. For that very reason, I have taken to welcoming new owners
here much as you might be welcomed there. So,

May the Good Lord bless this coach and all those that set forth within her.

Welcome Robert

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[bill wevers]

Hello Robert,
Welcome to this forum.
I have a few comments about the stress.
The radius of the lower control arm on the stock suspension is more like 15 inches.
The radius of the " " " on the one ton is a little less than 18 inches.
The wheel spacers are more like 3.5". Alcoa wheels may have more backspace than stock.
The one-ton front track width is close to 81.5 inches, which is 6 inches wider than stock.

The diameter of Peter's torsion bar is 1.27".

Using the above measurements, I get max stress of 93,000 PSI for the stock suspension.
And with the one-ton it's 111,600 PSI.
With Peters torsion bars it's only 94,144 PSI.

Regards,
Bill

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

 

[rob_abney]

Hi Matt, thanks for the welcome! Amen to that blessing! I will update my info in the signature in just a few !

Hi Bill - thanks as well. I'll double check my measurements. I could have made a mistake, I did use the tape measure and somehow it's easy to read the
wrong numbers. But to clarify, the lever length we are referring to is from the LCA bolt to the center of the tire. My one ton setup uses the factory
GM steel dually spacer and its about 4.25"

I understand the 1.27" bar will reduce stress but it is still low regarding wheel rate. Wheel rate is proportional to Length Squared whereas stress is
proportional to Length.

--
1978 GMC Royale
Purchased 5-05-2017

 

[rob_abney]

Hi guys,

I just took some measurements of the front track etc. I measured my coach but also a 75 transmode (in the back as future project- its a good reference
for stock setup on steel wheels)

Coach (78 royale):
Front Track (After 1-Ton): 83.5"
Center of Front Tire to Front LCA mounting bolt : 20.25"
Distance between Driver and Pass Front LCA Mounting Bolts (across frame): 43"

75 Transmode:
Front Track: 74.5"
Center of front tire to Front LCA mounting bolt: 15.75"

So my measurements are pretty close to what I used in the calculations. I'd be interested if yours are much different. One thing worth mentioning is
at lower ride height, the track width (lever arm) gets longer as the LCA approaches perfectly horizontal. This pushes the tire out farther. This is my
current state... with Stock TB's on the one-ton.

While at it I measured my ride heights:
Rear:
Spec per factory manual: 11-11/16
Measured: 11-11/16 (set to spec)

Front:
Spec: 13-1/8"
Measured: 11" (adjustable keys maxed out (porkchops))

So it turns out i'm a little over 2" low in the front.... no wonder I dragged my tranny pan across a speed bump...

--
Robert Abney , Austin, TX
78’ Royale, rear bath 403
Purchased 5/2017
One-Ton, copied off Stand Edwards and modified for increased caster and negative camber.

 

[Jim Hupy]

What about your anti-dive capability? 2" low in the front is a very bad
thing. I don't give a rusty rat's behind how it looks. It is supposed to be
high in the front. But, do all the math you want. It is kinda still a free
country.
Jim Hupy
Salem, Oregon

On Tue, Apr 14, 2020, 3:14 PM Robert Abney via Gmclist <

> Hi guys,
>
> I just took some measurements of the front track etc. I measured my coach
> but also a 75 transmode (in the back as future project- its a good reference
> for stock setup on steel wheels)
>
> Coach (78 royale):
> Front Track (After 1-Ton): 83.5"
> Center of Front Tire to Front LCA mounting bolt : 20.25"
> Distance between Driver and Pass Front LCA Mounting Bolts (across frame):
> 43"
>
> 75 Transmode:
> Front Track: 74.5"
> Center of front tire to Front LCA mounting bolt: 15.75"
>
> So my measurements are pretty close to what I used in the calculations.
> I'd be interested if yours are much different. One thing worth mentioning is
> at lower ride height, the track width (lever arm) gets longer as the LCA
> approaches perfectly horizontal. This pushes the tire out farther. This is
> my
> current state... with Stock TB's on the one-ton.
>
> While at it I measured my ride heights:
> Rear:
> Spec per factory manual: 11-11/16
> Measured: 11-11/16 (set to spec)
>
> Front:
> Spec: 13-1/8"
> Measured: 11" (adjustable keys maxed out (porkchops))
>
> So it turns out i'm a little over 2" low in the front.... no wonder I
> dragged my tranny pan across a speed bump...
>
>
>
>
> --
> Robert Abney , Austin, TX
> 78’ Royale, rear bath 403
> Purchased 5/2017
> One-Ton, copied off Stand Edwards and modified for increased caster and
> negative camber.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[rob_abney]

Hi Jim,

I'm not sure what you are getting at? My point is I can't raise the front any higher without a torsion bar upgrade. That's actually what this whole
discussion is about.... Not looks.

Regards

Robert

--
Robert Abney , Austin, TX
78’ Royale, rear bath 403
Purchased 5/2017
One-Ton, copied off Stand Edwards and modified for increased caster and negative camber.

 

[Jim Hupy]

Sorry, I don't always get all the messages about a particular thread. I was
going by your last entry, and did not see the earlier ones. Where are you
located? I have several sets of the Huber H.D. bars in stock.
Jim Hupy
Salem, Oregon

On Tue, Apr 14, 2020 at 4:14 PM Robert Abney via Gmclist <

> Hi Jim,
>
> I'm not sure what you are getting at? My point is I can't raise the front
> any higher without a torsion bar upgrade. That's actually what this whole
> discussion is about.... Not looks.
>
> Regards
>
> Robert
>
> --
> Robert Abney , Austin, TX
> 78’ Royale, rear bath 403
> Purchased 5/2017
> One-Ton, copied off Stand Edwards and modified for increased caster and
> negative camber.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[bill wevers]

Robert,
The distance you measured from the LCA bushing to the center of the tire is 20.25 inch?
If you measure the distance parallel to the ground it should be less.
The front track on my rig is 81.5 inches, with wheel camber close to zero.
Your wheel spacers may be increasing the load on your torsion bars.

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