Home » Public Forums » GMCnet » [GMCnet] Torsion Bars
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| Re: [GMCnet] Torsion Bars [message #54050 is a reply to message #54045] |
Sun, 23 August 2009 14:31   |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Steve,
Oh oh!
The torsion bars in Double Trouble and the Blue Streak were installed the
opposite as you note below.
The ends marked L & R with the arrows came out of and went back into the
A-frames.
I just checked manual
X-7525 page 3A-19 Torsion Bar And/Or Crossmember Support
Removal / Installation
And I can't find where it specifically says which end goes where!
Removal step 12. notes: "Mark torsion bars accordingly"
Installation step 1. notes: " New torsion bars are stamped on one end with
an "R" for right or an "L" for left side.
I also checked Parts Book 78Z and it doesn't show anything.
I am not questioning the way you put them in as I can understand the logic
in installing them the way you note if the arrows show the way the torsion
bars twist after being loaded with the pork chop.
Do I REALLY need to remove mine and turn them around? :-(
Note: John Sharpe pulled his lower A-Frames out this morning and I'll see
which way the torsion bars were installed. John reckons that the bushings
are original.
Regards,
Rob Mueller
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
'75 Avion - USA - The Parts Coach TZE 365V100324
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Steven Ferguson
Sent: Sunday, August 23, 2009 1:34 PM
To: gmclist@temp.gmcnet.org
Subject: [GMCnet] Torsion Bars
I pulled my Torsion bars this morning (nothing better to do) and since
this question was asked a few weeks ago, here are some pix of the
right and left torsion bars. The end pictured goes into the pork
chops.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=30543
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: [GMCnet] Torsion Bars [message #54082 is a reply to message #54050] |
Sun, 23 August 2009 17:39 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Rob,
Don't know what to tell you. R & L wouldn't be there if it wasn't
important. Another thing that is important is to make sure the
torsion bar is 100% through the pork chop. Paint the marked end white
so you can see through the crossmember that the torsion bar is fully
seated.
I'm sure it's possible to replace these somehow without removing the
crossmember, but I found it easiest to remove the crossmember. Four
bolts and you can tap it back with a mallet. When I installed mine
this afternoon, I inserted the bar into the a frame, then pulled it
back about two inches. I set the crossmember in place, then used a
ratcheting tie down strap and put forward tension on the crossmember.
Then I tapped the crossmember enough to just get the T bar started and
hang the porkchop on the hex, then kept tension on the tie down while
I rapped the crossmember home. This way ensured that the T bar was
fully seated in the pork chop. If the T bar doesn't line up
laterally, wrap another tie down around it an pull it towards the hole
in the crossmember. Saves a lot of cussing. If it's too low to line
up with the hole, put a jack with a rag on the cradle under it and
raise it up. The whole idea is not to nick the T bar. I have read
that when nicked, the nick tends to behave like a chip in a windshield
(weak spot). Don't give a thought to all the dirt and grease under
there........you'll be wearing it when you're done and the GMC will be
nice and clean underneath:>)
On Sun, Aug 23, 2009 at 12:31 PM, Rob Mueller<robmueller@iinet.net.au> wrote:
> Steve,
>
> Oh oh!
>
> The torsion bars in Double Trouble and the Blue Streak were installed the
> opposite as you note below.
>
> The ends marked L & R with the arrows came out of and went back into the
> A-frames.
>
> I just checked manual
>
> X-7525 page 3A-19 Torsion Bar And/Or Crossmember Support
>
> Removal / Installation
>
> And I can't find where it specifically says which end goes where!
>
> Removal step 12. notes: "Mark torsion bars accordingly"
>
> Installation step 1. notes: " New torsion bars are stamped on one end with
> an "R" for right or an "L" for left side.
>
> I also checked Parts Book 78Z and it doesn't show anything.
>
> I am not questioning the way you put them in as I can understand the logic
> in installing them the way you note if the arrows show the way the torsion
> bars twist after being loaded with the pork chop.
>
> Do I REALLY need to remove mine and turn them around? :-(
>
> Note: John Sharpe pulled his lower A-Frames out this morning and I'll see
> which way the torsion bars were installed. John reckons that the bushings
> are original.
>
> Regards,
> Rob Mueller
> Sydney, Australia
> '75 Avion - AUS - The Blue Streak TZE365V100428
> '75 Avion - USA - Double Trouble TZE365V100426
> '75 Avion - USA - The Parts Coach TZE 365V100324
>
> -----Original Message-----
> From: gmclist-bounces@temp.gmcnet.org
> [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Steven Ferguson
> Sent: Sunday, August 23, 2009 1:34 PM
> To: gmclist@temp.gmcnet.org
> Subject: [GMCnet] Torsion Bars
>
> I pulled my Torsion bars this morning (nothing better to do) and since
> this question was asked a few weeks ago, here are some pix of the
> right and left torsion bars. The end pictured goes into the pork
> chops.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=30543
>
> --
> Steve Ferguson
> '76 EII
> Sierra Vista, AZ
> Urethane bushing source
> www.bdub.net/ferguson/
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: [GMCnet] Torsion Bars [message #54093 is a reply to message #54045] |
Sun, 23 August 2009 18:11 |
Carleton Douglas[1]
Messages: 174
Registered: March 2006
Karma: 0
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Senior Member |
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Steve,
My 73 has no ID at all on the Torsion bars, had them in and out a few times.
On Sun, Aug 23, 2009 at 11:34 AM, Steven Ferguson<botiemad11@gmail.com> wrote:
> I pulled my Torsion bars this morning (nothing better to do) and since
> this question was asked a few weeks ago, here are some pix of the
> right and left torsion bars. The end pictured goes into the pork
> chops.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=30543
>
> --
> Steve Ferguson
> '76 EII
> Sierra Vista, AZ
> Urethane bushing source
> www.bdub.net/ferguson/
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Carleton Douglas
73 custom, by myself
Prescott, AZ
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| Re: [GMCnet] Torsion Bars [message #54097 is a reply to message #54093] |
Sun, 23 August 2009 19:17 |
GMCWiperMan
Messages: 1248
Registered: December 2007
Karma: 1
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Senior Member |
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I'm surprised that any torsion bar is not marked for side because without
pre-stressing during manufacture, they would be much more prone to taking a
set during use.
I don't have a '73 maintenance manual, but X-7425 has these statements:
----------------------------------------------------
12. Remove torsion bars. Mark accordingly to
insure proper installation end for end and right and
left.
INSTALLATION
1 . Install torsion bars. New torsion bars are
stamped on one end with an "R" for right or an "L"
for left side. Apply a liberal amount of chassis grease
----------------------------------------------------
I wonder if the statement "New...stamped..." has any significance? I
seriously doubt it because they needed some way to identify them on the
production line.
X-7625 and X-7725 have slightly different wording which no longer mentions
orientation F/R or L/R for marking removed bars:
----------------------------------------------------
12. Remove torsion bars. Mark accordingly
to insure proper installation.
INSTALLATION
1. Install torsion bars. New torsion bars are
stamped on one end with an "R" for right or an
"L" for left side. Apply a liberal amount of
chassis grease to both ends.
----------------------------------------------------
I still contend that orientation front to rear makes no difference; left to
right definitely does.
Ken Henderson
Americus, GA
GMCWipersEtc.com
’76 X-Birchaven
-----Original Message-----
Steve,
My 73 has no ID at all on the Torsion bars, had them in and out a few times.
On Sun, Aug 23, 2009 at 11:34 AM, Steven Ferguson<botiemad11@gmail.com>
wrote:
> I pulled my Torsion bars this morning (nothing better to do) and since
> this question was asked a few weeks ago, here are some pix of the
> right and left torsion bars. The end pictured goes into the pork
> chops.
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=30543
>
> --
> Steve Ferguson
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| Re: [GMCnet] Torsion Bars [message #54113 is a reply to message #54045] |
Sun, 23 August 2009 21:27 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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Senior Member |
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I took my torsion bars out today and...... the right bar's marking was in the pork chop. The marking for the left bar was in the a-frame. Go figure. If the arrow points toward the direction to raise the coach, it looks to me like the markings should be in the pork chop. Otherwise the arrow would be pointing in the direction to lower the coach and would not be seen when following the procedure of installing from the crossmember end. If the ends are switched front to rear, then the direction of the load on the bar is reversed. So.....I conclude that they should be installed with the markings at the rear. What does it say for 4X4 GMC pick-ups? Or Dodges? Whoever makes these things probably supplies everybody and marks them the same.
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: [GMCnet] Torsion Bars [message #54122 is a reply to message #54113] |
Sun, 23 August 2009 22:33 |
GMCWiperMan
Messages: 1248
Registered: December 2007
Karma: 1
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Y'All bear with me for a while and go through a test with me:
Most of you can conduct this experiment mentally, and have probably done so
consciously or unconsciously many times:
1. Secure one end of a strip of metal in a vice with most of the strip
extending to the right of the vice.
2. Grip the free end of the strip and twist it clockwise just a little,
then release it. The twist should not remain in the metal. If your metal
won't respond this way, it's too ductile; get a more "springy" piece.
3. Repeatedly twist the strip clockwise, a little farther each time, until
the twist remains after the force is released. The twist has now exceeded
the "yield point" of the metal; if you twist the strip much farther, it will
require less and less force for each degree of twist -- don't test that now.
What you have done is pre-stressed our mini torsion bar.
4. Now twist the free end counterclockwise to the original position in #1.
preceding. Hold that position. The force you must apply to hold that
position is analogous to the weight of the coach loading the torsion bar.
5. Twist a little more counterclockwise and you simulate a bump or
additional load applied to the torsion bar. When you ease off on the force,
the twist should naturally come out of the strip (torsion bar). If you ease
off too much (jack up the vehicle) the completely unloaded strip should
return to the pre-stressed condition of #3., preceding.
The point of all this is that by pre-stressing metal one can gain additional
range of motion without additional permanent deformation. With the proper
selection of metal alloy and heat treatment, a very durable device such as
our torsion bars can be developed. Without that pre-stressing, the torsion
bar could be twisted only to the degree achieved in #2., preceding.
6. Now take the twisted strip and reverse ends in the vice. You'll see
that the permanent twist is still clockwise and that it still takes a
counterclockwise force to relieve the strain caused by the pre-stressing.
Thus, it matters not which end of the torsion bar is forward.
That's why torsion bars are pre-stressed and have a marking on at least one
end (not necessarily both) to indicate the direction in which they are to be
loaded (located). Pre-stressing almost doubles the amount of twisting the
bar can withstand repeatedly without damage.
John, I'll bet if you lightly sand the ends of your torsion bars you will
find an L or an R. Marking the pork chop or the A-arm would be of no value
at all in determining the correct orientation of the torsion bar. I don't
think all of our torsion bars have direction arrows, but they should have L
or R.
Ken Henderson
Americus, GA
GMCWipersEtc.com
'76 X-Birchaven
-----Original Message-----
I took my torsion bars out today and...... the right bar's marking was in
the pork chop. The marking for the left bar was in the a-frame. Go figure.
If the arrow points toward the direction to raise the coach, it looks to me
like the markings should be in the pork chop. Otherwise the arrow would be
pointing in the direction to lower the coach and would not be seen when
following the procedure of installing from the crossmember end. If the ends
are switched front to rear, then the direction of the load on the bar is
reversed. So.....I conclude that they should be installed with the markings
at the rear. What does it say for 4X4 GMC pick-ups? Or Dodges? Whoever
makes these things probably supplies everybody and marks them the same.
--
John Sharpe
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| Re: [GMCnet] Torsion Bars [message #54233 is a reply to message #54134] |
Mon, 24 August 2009 22:08 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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Senior Member |
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Steve, On the bar with the markings on the A frame end the adjusting screw had 1.0825" of bolt still showing. On the bar with the markings on the porkchop end the adjusting screw had .6875" of bolt showing. I set the ride height at Bean Station in May and Alex Sirum weighed it in Dothan in March and the weights were within 50# side to side.
When I saw Ken's first response, I read it differently than what he wrote. I think we are all on the same page just speaking different dialects.
Now, does from what Ken described as 'having more motion' explain why the bar installed opposite of the arrow direction required less adjustment or is that measurement really not related to anything on a 30+ year old vehicle?
Sorry for you e-mailers for not including all the previous discussion. If you're interested go to: http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=8049&start=0&rid=941
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: [GMCnet] Torsion Bars [message #54234 is a reply to message #54233] |
Mon, 24 August 2009 22:22 |
GMCWiperMan
Messages: 1248
Registered: December 2007
Karma: 1
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Senior Member |
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John,
I apologize -- I misread your message as saying there were location marks
(L&R) on the pork chop itself, not on the pork chop end -- and likewise on
the A-frame end.
We seem to still have a difference of opinion about whether end-for-end
reversal matters. I tried my twisted metal experiment (with a piece of
stiff paper) and am absolutely convinced that it makes no difference -- the
loading is the same.
To me, the difference in adjustment screw position you see is insignificant.
I'm sure mine are much farther apart. After 30 years of potholes, shoulder
drop offs, and other abuses, I'd think it amazing if two torsion bars, of
unknown manufacturing lots, etc., were of the same strength.
If we had that sort of precise manufacturing, no one should ever have to
replace a broken torsion bar -- they'd always both break at the same time!
:-)
Ken Henderson
Americus, GA
GMCWipersEtc.com
'76 X-Birchaven
-----Original Message-----
Steve, On the bar with the markings on the A frame end the adjusting screw
had 1.0825" of bolt still showing. On the bar with the markings on the
porkchop end the adjusting screw had .6875" of bolt showing. I set the ride
height at Bean Station in May and Alex Sirum weighed it in Dothan in March
and the weights were within 50# side to side.
When I saw Ken's first response, I read it differently than what he wrote.
I think we are all on the same page just speaking different dialects.
Now, does from what Ken described as 'having more motion' explain why the
bar installed opposite of the arrow direction required less adjustment or
is that measurement really not related to anything on a 30+ year old
vehicle?
Sorry for you e-mailers for not including all the previous discussion. If
you're interested go to:
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&th=8049&start=0&rid=941
--
John Sharpe
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| Re: [GMCnet] Torsion Bars [message #54263 is a reply to message #54233] |
Tue, 25 August 2009 08:36 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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John,
I also had one reversed. The L one was in with the markings in the A
arm end. After turning it around, it took almost exactly the same
amount of turns to adjust ride height. I'm not an expert on this
stuff by any means but for darn sure I'd hate to replace one of these
things on the road. I remember when Henry Davis snapped one at his
usual mach 1 freeway speeds. I'd just as soon put them in the way
they are supposed to be and reduce the risk. If for nothing else, it
makes for more peace of mind. BTW, for some reason, my coach is off
by 150 lbs side to side in the front. When I first got the coach,
that left one was screwed up so tight it had pigtailed.
On Mon, Aug 24, 2009 at 8:08 PM, John Sharpe<johnasharpe@earthlink.net> wrote:
Steve, On the bar with the markings on the A frame end the adjusting
screw had 1.0825" of bolt still showing. On the bar with the markings
on the porkchop end the adjusting screw had .6875" of bolt showing. I
set the ride height at Bean Station in May and Alex Sirum weighed it
in Dothan in March and the weights were within 50# side to side.
Now, does from what Ken described as 'having more motion' explain why
the bar installed opposite of the arrow direction required less
adjustment or is that measurement really not related to anything on a
30+ year old vehicle?
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: [GMCnet] Torsion Bars [message #54274 is a reply to message #54263] |
Tue, 25 August 2009 09:56 |
tmaki
Messages: 200
Registered: September 2005
Karma: 0
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Senior Member |
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Steven Ferguson wrote:
> I'd hate to replace one of these
> things on the road. I remember when Henry Davis snapped one at his
> usual mach 1 freeway speeds.
Yeah, I'd say so. When mine snapped 50 miles west of Houston
during the holidays in '99, it was a real inconvenience
for us, the family members we were visiting in League City,
and the little barbecue place where I parked the coach in
the dirt.
It wasn't so much the trouble of fixing it - which was bad
enough - it was the near impossible prospects of finding one
over Christmas that caused the most concern. I can never
thank Duane Simmons and the Ruppel family for coming to our aid.
I still contend that the wear spot on the bar caused by
years of contact with the support struts below was a major
factor in creating a defect that led to the failure. That's
where the bar snapped, and very close examination showed
stress damage that I am convinced shortened the life of the
bar. As as aside, since I've been underneath working on the
fuel system, I've noticed that the right side strut is now
broken in two. I'm not sure what caused that, but I'm going
to look at that torsion bar for the defect.
I'd advise anybody who is concerned to get under there and
examine the torsion bar surface where the diagonal strut
runs. Check for a dent, nick, worn spot, etc. There's
probably nothing you can do about it, but at least if the
bar snaps, one can be prepared - like being prepared for a
tire blowout.
When a failure occurs, it feels like a total front tire
blowout. BANG!, slight swerve, side goes down like a flat
tire. Coach will probably still be quite steerable, but sure
looks funny with the wheel as crooked as it's going to be.
Run the mental simulation like you would for a tire blowout.
Cleaning of upholstery where seated occupants were will also
be advised.
Toby Maki
'73 Glacier 230
Riverside, CA
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| Re: [GMCnet] Torsion Bars [message #54276 is a reply to message #54274] |
Tue, 25 August 2009 10:05 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
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Senior Member |
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Toby,
Are the T bars the same for both the 23 and 26?
Thanks
Gary and Joanne Worobec
1973 GMC Glacier
----- Original Message -----
From: "tmaki" <tmaki@earthlink.net>
To: <gmclist@temp.gmcnet.org>
Sent: Tuesday, August 25, 2009 7:56 AM
Subject: Re: [GMCnet] Torsion Bars
> Steven Ferguson wrote:
>
>
>> I'd hate to replace one of these
>> things on the road. I remember when Henry Davis snapped one at his
>> usual mach 1 freeway speeds.
>
> Yeah, I'd say so. When mine snapped 50 miles west of Houston
> during the holidays in '99, it was a real inconvenience
> for us, the family members we were visiting in League City,
> and the little barbecue place where I parked the coach in
> the dirt.
>
> It wasn't so much the trouble of fixing it - which was bad
> enough - it was the near impossible prospects of finding one
> over Christmas that caused the most concern. I can never
> thank Duane Simmons and the Ruppel family for coming to our aid.
>
> I still contend that the wear spot on the bar caused by
> years of contact with the support struts below was a major
> factor in creating a defect that led to the failure. That's
> where the bar snapped, and very close examination showed
> stress damage that I am convinced shortened the life of the
> bar. As as aside, since I've been underneath working on the
> fuel system, I've noticed that the right side strut is now
> broken in two. I'm not sure what caused that, but I'm going
> to look at that torsion bar for the defect.
>
> I'd advise anybody who is concerned to get under there and
> examine the torsion bar surface where the diagonal strut
> runs. Check for a dent, nick, worn spot, etc. There's
> probably nothing you can do about it, but at least if the
> bar snaps, one can be prepared - like being prepared for a
> tire blowout.
>
> When a failure occurs, it feels like a total front tire
> blowout. BANG!, slight swerve, side goes down like a flat
> tire. Coach will probably still be quite steerable, but sure
> looks funny with the wheel as crooked as it's going to be.
> Run the mental simulation like you would for a tire blowout.
>
> Cleaning of upholstery where seated occupants were will also
> be advised.
>
>
>
>
> Toby Maki
> '73 Glacier 230
> Riverside, CA
> _______________________________________________
> GMCnet mailing list
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| Re: [GMCnet] Torsion Bars [message #54280 is a reply to message #54276] |
Tue, 25 August 2009 10:25 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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Yes.
On Tue, Aug 25, 2009 at 8:05 AM, Gary Worobec<gtw5@earthlink.net> wrote:
> Toby,
> Are the T bars the same for both the 23 and 26?
>
> Thanks
>
> Gary and Joanne Worobec
> 1973 GMC Glacier
>
> ----- Original Message -----
> From: "tmaki" <tmaki@earthlink.net>
> To: <gmclist@temp.gmcnet.org>
> Sent: Tuesday, August 25, 2009 7:56 AM
> Subject: Re: [GMCnet] Torsion Bars
>
>
>> Steven Ferguson wrote:
>>
>>
>>> I'd hate to replace one of these
>>> things on the road. I remember when Henry Davis snapped one at his
>>> usual mach 1 freeway speeds.
>>
>> Yeah, I'd say so. When mine snapped 50 miles west of Houston
>> during the holidays in '99, it was a real inconvenience
>> for us, the family members we were visiting in League City,
>> and the little barbecue place where I parked the coach in
>> the dirt.
>>
>> It wasn't so much the trouble of fixing it - which was bad
>> enough - it was the near impossible prospects of finding one
>> over Christmas that caused the most concern. I can never
>> thank Duane Simmons and the Ruppel family for coming to our aid.
>>
>> I still contend that the wear spot on the bar caused by
>> years of contact with the support struts below was a major
>> factor in creating a defect that led to the failure. That's
>> where the bar snapped, and very close examination showed
>> stress damage that I am convinced shortened the life of the
>> bar. As as aside, since I've been underneath working on the
>> fuel system, I've noticed that the right side strut is now
>> broken in two. I'm not sure what caused that, but I'm going
>> to look at that torsion bar for the defect.
>>
>> I'd advise anybody who is concerned to get under there and
>> examine the torsion bar surface where the diagonal strut
>> runs. Check for a dent, nick, worn spot, etc. There's
>> probably nothing you can do about it, but at least if the
>> bar snaps, one can be prepared - like being prepared for a
>> tire blowout.
>>
>> When a failure occurs, it feels like a total front tire
>> blowout. BANG!, slight swerve, side goes down like a flat
>> tire. Coach will probably still be quite steerable, but sure
>> looks funny with the wheel as crooked as it's going to be.
>> Run the mental simulation like you would for a tire blowout.
>>
>> Cleaning of upholstery where seated occupants were will also
>> be advised.
>>
>>
>>
>>
>> Toby Maki
>> '73 Glacier 230
>> Riverside, CA
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--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: [GMCnet] Torsion Bars [message #54282 is a reply to message #54280] |
Tue, 25 August 2009 10:40 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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Senior Member |
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| Quote: |
Ken wrote: We seem to still have a difference of opinion about whether end-for-end
reversal matters.
|
Ken, the markings on my torsion bar for the left side were on the A frame end. It showed L and a counterclockwise pointing arrow. To me this showed that it was in opposite because the arrow is pointing in the direction of lowering the coach. Now if this bar has been run backwards should I re-install it or change it to the orientation that is marked on the bar?
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: [GMCnet] Torsion Bars [message #54283 is a reply to message #54274] |
Tue, 25 August 2009 10:42 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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Excellent point Toby. I have yet to look under a GMC and not see one
of those front struts bent. I had a custom set made up for mine, much
smaller, same, if not more strength. My original ones were severely
bent so I replaced them with some I made from channel iron. I got a
Black list call last fall and the guy was stranded with one that was
beyond hope (he ran over something) so I pulled mine off and he came
and got them.
Here's a couple of pix:
http://www.gmcmhphotos.com/photos/showgallery.php?cat=5257
On Tue, Aug 25, 2009 at 7:56 AM, tmaki<tmaki@earthlink.net> wrote:
Yeah, I'd say so. When mine snapped 50 miles west of Houston
during the holidays in '99, it was a real inconvenience
for us, the family members we were visiting in League City,
and the little barbecue place where I parked the coach in
the dirt.
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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| Re: [GMCnet] Torsion Bars [message #54293 is a reply to message #54290] |
Tue, 25 August 2009 11:49 |
Gary Worobec
Messages: 867
Registered: May 2005
Karma: -1
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Senior Member |
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I think these struts would be much better if you could load them with a
turnbuckle or a link with rod ends. Seems to me they are to keep the front
clip from movement in the frame rails. Only reason I could see to have them.
I've got to assume they were not a retrofit as I have early 73 that has
them.
Thanks
Gary and Joanne Worobec
1973 GMC Glacier
----- Original Message -----
From: "tmaki" <tmaki@earthlink.net>
To: <gmclist@temp.gmcnet.org>
Sent: Tuesday, August 25, 2009 9:42 AM
Subject: Re: [GMCnet] Torsion Bars
> Steven Ferguson wrote:
>
>> I had a custom set made up for mine, much
>> smaller, same, if not more strength. My original ones were severely
>> bent so I replaced them with some I made from channel iron.
>
>
> Not to stray too far off topic, but I've been thinking about
> a different arrangement of these struts. Maybe I'm having an
> obtuse attack, but I've never been able to define the
> specific purpose for these struts, except to keep the
> underside from flopping around - maybe like those support
> rods that used to run diagonally across the top of the
> engine compartment of '60's and '70's era Cadillacs with
> all the space way out in front.
>
> My Dodge van has similar struts, but they are much mobigga
> especially for an 8250 GVWR frame. I'm thinking of maybe
> modding the GMC to something like that.
>
> I don't now - I just wish I knew how important these things
> are in the whole scheme of things. I can't see how they
> really have a suspension system purpose as they can be bent
> pretty easily.
>
> Willing to be educated...
>
>
>
> Toby Maki
> '73 Glacier 230
> Riverside, CA
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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