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| [GMCnet] 1-ton installation - TB [message #153575] |
Mon, 19 December 2011 17:04  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
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I've changed the subject to start a new thread since the old "1-ton
instatllation" was becoming too long, IMHO.
There must be something I've missed during all of these discussions,
because what I THINK I know now seems to lead to a simple solution to the
Torsion Bar problem, both for the 1-ton suspension upgrade and for
un-modified GMC's..
From the table below, it appears that the Chevrolet/GMC truck Torsion Bars
(TB's) should fit right into our A-arm sockets and our pork chops, with
just one minor problem: They're only 54" long and ours are 58-1/4" long.
But the Chevy TB's are available in a wide variety of torque ratings, are
readily available all over the country, and are, probably, still being
produced. The wonderful fact is that it apparently requires only the
drilling of 6 each 3/8" holes in the web of the GMC's chassis side rails to
allow us to fit the Chevy torsion bars!
http://www.gmfullsize.com/tech/torsion401.html
Now before I go into the simple details of that modification, someone
please tell me why Bill Hubler, to utilize Chevy torsion bars, welded in a
new socket -- I thought it was because those TB's had bigger hexes but
that's apparently not the case.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
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76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153580 is a reply to message #153575] |
Mon, 19 December 2011 17:47  |
James Hupy
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Registered: May 2010
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Ken, when I talked to Bill at Palm Desert, he had the control Arm that he
modified the socket there, and I looked at it carefully. What he told me as
the reason he extended the torsion bar socket, was to make the use of the
late model 1 ton TB's without moving the crossmember. Don't know whether
his Diesel Conversion required the crossmember to stay in place or not. But
I kinda think like you do that it should be a simple matter to redrill the
frame further forward, slide the crossmember forward to accomodate the
shorter torsion bars, and be done with it. If you use the "keys" that come
with the torsion bars, they will have to be ground slightly on the top to
clear the inside of the crossmember, and the hole in the crossmember that
the TB goes through will have to be enlarged a slight amount. Other than
that, it appears to be a direct bolt in replacement. Has Manny sent you a
replacement lower control arm yet?
Jim Hupy
Salem, OR
78 GMC Royale 403
On Mon, Dec 19, 2011 at 3:04 PM, Ken Henderson <hend4800@bellsouth.net>wrote:
> I've changed the subject to start a new thread since the old "1-ton
> instatllation" was becoming too long, IMHO.
>
> There must be something I've missed during all of these discussions,
> because what I THINK I know now seems to lead to a simple solution to the
> Torsion Bar problem, both for the 1-ton suspension upgrade and for
> un-modified GMC's..
>
> From the table below, it appears that the Chevrolet/GMC truck Torsion Bars
> (TB's) should fit right into our A-arm sockets and our pork chops, with
> just one minor problem: They're only 54" long and ours are 58-1/4" long.
> But the Chevy TB's are available in a wide variety of torque ratings, are
> readily available all over the country, and are, probably, still being
> produced. The wonderful fact is that it apparently requires only the
> drilling of 6 each 3/8" holes in the web of the GMC's chassis side rails to
> allow us to fit the Chevy torsion bars!
> http://www.gmfullsize.com/tech/torsion401.html
>
> Now before I go into the simple details of that modification, someone
> please tell me why Bill Hubler, to utilize Chevy torsion bars, welded in a
> new socket -- I thought it was because those TB's had bigger hexes but
> that's apparently not the case.
>
> Ken H.
> Americus, GA
> '76 X-Birchaven w/Cad500/Howell EFI+ & EBL
> www.gmcwipersetc.com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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| Re: [GMCnet] 1-ton installation - TB [message #153583 is a reply to message #153580] |
Mon, 19 December 2011 18:34 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
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Jim,
When I talked to Bill and looked at what he'd done at Santa Rosa, I really
didn't dwell on the details; now I wish I had. Maybe beyond avoiding
moving the cross member he was also precluding problems with the old socket?
I just made pictures of the #4 (pork chop) cross member and the bracket to
which it's attached to post for those who are not familiar with those
details. On my 23', I see no reason the cross member can't be moved
forward 6" or aft 2" -- just drill 3 new 3/8" holes in the web of each side
rail and bolt it up.
You've partially answered one more of the questions I still had: I
wondered what the differences are between our "pork chops" and the Chevy
"keys". Is the keys' radius to the adjustment bolt socket the same as the
pork chops', or must the "nut" be moved? When I thought I was about to
install JimK's adjustable pork chops, I noticed that, as you say, the lower
side of the TB hole would have to be enlarged. I didn't get far enough
into that to tell how much, nor whether the top of the PC or the cross
member would have to be modified. JimK, can you answer those Q's?
Manny shipped me a replacement A-arm last week. With typical efficiency,
UPS says it will be here Thursday. Took less time to truck freight the
315# crate with the whole kit. The southwestern blizzard should get here
about the same time. :-(
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
On Mon, Dec 19, 2011 at 6:47 PM, James Hupy <jamesh1296@gmail.com> wrote:
> Ken, when I talked to Bill at Palm Desert, he had the control Arm that he
> modified the socket there, and I looked at it carefully. What he told me as
> the reason he extended the torsion bar socket, was to make the use of the
> late model 1 ton TB's without moving the crossmember. Don't know whether
> his Diesel Conversion required the crossmember to stay in place or not. But
> I kinda think like you do that it should be a simple matter to redrill the
> frame further forward, slide the crossmember forward to accomodate the
> shorter torsion bars, and be done with it. If you use the "keys" that come
> with the torsion bars, they will have to be ground slightly on the top to
> clear the inside of the crossmember, and the hole in the crossmember that
> the TB goes through will have to be enlarged a slight amount. Other than
> that, it appears to be a direct bolt in replacement. Has Manny sent you a
> replacement lower control arm yet?
> Jim Hupy
> Salem, OR
> 78 GMC Royale 403
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Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153588 is a reply to message #153583] |
Mon, 19 December 2011 19:14 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
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It occurred to me today that some who are following this thread may not be
familiar with the details of how the torsion bars, pork chops, and
associated hardware are arranged. The photos didn't all come out too good,
but the better, most important of them are posted at:
http://www.gmcmhphotos.com/photos/showgallery.php?cat=5973
Perhaps they'll at least demonstrate how easy it would be to move the cross
member forward or rearward as necessary to re-seat the OEM TB's or to
accommodate different length bars -- just drill 3 new 3/8" holes in the web
of the side rail on each side.
Ken H.
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Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153595 is a reply to message #153588] |
Mon, 19 December 2011 20:02 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
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Ken,
IIRC the first person to install the Maxx Suspension pork chops noted that they were a bit wider than the ID of the cross member and
he had to spread the cross member to make them fit. Since you have access to all the parts at the moment could you please take the
measurements of:
1) width of the OEM pork chops
2) width of the Maxx Suspension pork chops
3) ID width of the cross member
Regards,
Rob M.
-----Original Message-----
From: Of Ken Henderson
It occurred to me today that some who are following this thread may not be
familiar with the details of how the torsion bars, pork chops, and
associated hardware are arranged. The photos didn't all come out too good,
but the better, most important of them are posted at:
http://www.gmcmhphotos.com/photos/showgallery.php?cat=5973
Perhaps they'll at least demonstrate how easy it would be to move the cross
member forward or rearward as necessary to re-seat the OEM TB's or to
accommodate different length bars -- just drill 3 new 3/8" holes in the web
of the side rail on each side.
Ken H.
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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] 1-ton installation - TB [message #153603 is a reply to message #153575] |
Mon, 19 December 2011 20:40 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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I'm sure this will be a long thread as well but hey, that's a good thing. Ken, you know this but you will run into differences in not only rate, but static height as well and they are mostly independent. It's harder to visualize as a torsion bar but in reality it is identical to a coil spring that has been straightened out. Routinely in production, we may have 10 part numbers which specify the ride height based on vehicle options and then we will repeat that for various suspension packages that have different rates. Torsion bars help a bit in that you can adjust the ride height with the same p/n within reason. Without the actual engineering specs it becomes a bit of a crap shoot but frankly, I think the GMC could use higher rate springs and benefit, It may come down to a trial and error thing but I'm sure you will find a best solution and balance.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] 1-ton installation - TB [message #153604 is a reply to message #153595] |
Mon, 19 December 2011 20:39 |
Carleton Douglas[1]
Messages: 174
Registered: March 2006
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Good for you Ken.
On Mon, Dec 19, 2011 at 7:02 PM, Rob Mueller <robmueller@iinet.net.au> wrote:
> Ken,
>
> IIRC the first person to install the Maxx Suspension pork chops noted that they were a bit wider than the ID of the cross member and
> he had to spread the cross member to make them fit. Since you have access to all the parts at the moment could you please take the
> measurements of:
>
> 1) width of the OEM pork chops
> 2) width of the Maxx Suspension pork chops
> 3) ID width of the cross member
>
> Regards,
> Rob M.
>
> -----Original Message-----
> From: Of Ken Henderson
>
> It occurred to me today that some who are following this thread may not be
> familiar with the details of how the torsion bars, pork chops, and
> associated hardware are arranged. The photos didn't all come out too good,
> but the better, most important of them are posted at:
>
> http://www.gmcmhphotos.com/photos/showgallery.php?cat=5973
>
> Perhaps they'll at least demonstrate how easy it would be to move the cross
> member forward or rearward as necessary to re-seat the OEM TB's or to
> accommodate different length bars -- just drill 3 new 3/8" holes in the web
> of the side rail on each side.
>
> Ken H.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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--
Carleton Douglas
73 custom, by myself
Prescott, AZ
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| Re: [GMCnet] 1-ton installation - TB [message #153610 is a reply to message #153604] |
Mon, 19 December 2011 21:04 |
Don Walton
Messages: 50
Registered: September 2007
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Thanks for the pictures, they did clear up a lot for me. I would like to install a one ton set up and am trying to learn everything I can before taking the plunge. Keep up the great posts!
Don Walton in NC,
75 Glenbrook,
too many MGs
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| Re: [GMCnet] 1-ton installation - TB [message #153613 is a reply to message #153603] |
Mon, 19 December 2011 21:09 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Bob,
The ready availability of a wide range of torque ratings on the bars is one
of the main reasons I think converting to the Chevy TB is the best way to
go. I understand there have been heavier TB's made in the past, and
there's some current investigation going on, but specifying one certainly
won't be based on sound engineering. Experimentation using what's
available seems to me to be more logical.
I'm thinking we should try to find a new TB with a rating greater in the
same proportion as we're increasing the lever arm. That is, if the wider
tread makes the lever arm 25% greater, we need a 4000*1.25=5000 ft.lb. TB.
Is that reasonable?
Yeah, it's hard for most folks to relate a torsion bar to a coil spring.
I'm surprised no one has questioned my assertion of the same principle
yesterday about the sway bar. :-)
Thanks for your help.
Ken
On Mon, Dec 19, 2011 at 9:40 PM, Bob de Kruyff <NEXT2POOL@aol.com> wrote:
>
>
> I'm sure this will be a long thread as well but hey, that's a good thing.
> Ken, you know this but you will run into differences in not only rate, but
> static height as well and they are mostly independent. It's harder to
> visualize as a torsion bar but in reality it is identical to a coil spring
> that has been straightened out. Routinely in production, we may have 10
> part numbers which specify the ride height based on vehicle options and
> then we will repeat that for various suspension packages that have
> different rates. Torsion bars help a bit in that you can adjust the ride
> height with the same p/n within reason. Without the actual engineering
> specs it becomes a bit of a crap shoot but frankly, I think the GMC could
> use higher rate springs and benefit, It may come down to a trial and error
> thing but I'm sure you will find a best solution and balance.
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153621 is a reply to message #153613] |
Mon, 19 December 2011 21:26 |
Kosier
Messages: 834
Registered: February 2008
Karma: 1
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Ken,
Bill Hubler's presentation on the GMCWS website says it's an
1&3/4" socket.
Perhaps there are different bar sizes in different years. The
pictures also
show a size difference. Who knows???
Gary Kosier
----- Original Message -----
From: "Ken Henderson" <hend4800@bellsouth.net>
To: <gmclist@temp.gmcnet.org>
Sent: Monday, December 19, 2011 10:09 PM
Subject: Re: [GMCnet] 1-ton installation - TB
> Bob,
>
> The ready availability of a wide range of torque ratings on the
> bars is one
> of the main reasons I think converting to the Chevy TB is the
> best way to
> go. I understand there have been heavier TB's made in the
> past, and
> there's some current investigation going on, but specifying one
> certainly
> won't be based on sound engineering. Experimentation using
> what's
> available seems to me to be more logical.
>
> I'm thinking we should try to find a new TB with a rating
> greater in the
> same proportion as we're increasing the lever arm. That is, if
> the wider
> tread makes the lever arm 25% greater, we need a 4000*1.25=5000
> ft.lb. TB.
> Is that reasonable?
>
> Yeah, it's hard for most folks to relate a torsion bar to a
> coil spring.
> I'm surprised no one has questioned my assertion of the same
> principle
> yesterday about the sway bar. :-)
>
> Thanks for your help.
>
> Ken
>
>
> On Mon, Dec 19, 2011 at 9:40 PM, Bob de Kruyff
> <NEXT2POOL@aol.com> wrote:
>
>>
>>
>> I'm sure this will be a long thread as well but hey, that's a
>> good thing.
>> Ken, you know this but you will run into differences in not
>> only rate, but
>> static height as well and they are mostly independent. It's
>> harder to
>> visualize as a torsion bar but in reality it is identical to a
>> coil spring
>> that has been straightened out. Routinely in production, we
>> may have 10
>> part numbers which specify the ride height based on vehicle
>> options and
>> then we will repeat that for various suspension packages that
>> have
>> different rates. Torsion bars help a bit in that you can
>> adjust the ride
>> height with the same p/n within reason. Without the actual
>> engineering
>> specs it becomes a bit of a crap shoot but frankly, I think
>> the GMC could
>> use higher rate springs and benefit, It may come down to a
>> trial and error
>> thing but I'm sure you will find a best solution and balance.
>> --
>> Bob de Kruyff
>> 78 Eleganza
>> Chandler, AZ
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
> _______________________________________________
> GMCnet mailing list
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| Re: [GMCnet] 1-ton installation - TB [message #153622 is a reply to message #153621] |
Mon, 19 December 2011 21:28 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
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Someone needs to discuss this whole thing with Bill. Manny?
Ken H.
On Mon, Dec 19, 2011 at 10:26 PM, Kosier wrote:
>
>
> Bill Hubler's presentation on the GMCWS website says it's an
> 1&3/4" socket.
> Perhaps there are different bar sizes in different years. The
> pictures also
> show a size difference. Who knows???
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Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153626 is a reply to message #153613] |
Mon, 19 December 2011 21:37 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
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I agree totally Ken--I don't think it will be too difficult for you to find a good compromize and yes, in this case I think a higher rate would be preferable. Spring rate is interesting in that it rarely affects ride the way we think it will. Spring rate will affect roll rate (we could use more) and it will affect ride motion frequency(in other words between 1 and 2 HZ) Impacts are primarily controlled by geometry and bushings. Most vehicles have a ride frequency of 1HZ in the front and 1.2 in the rear in order to keep a level ride motion. Lower ride rates tend to cause motion sickness and that's one reason people experience less of that in the rear. Shock valving can control the degree of motion but the rate of motion is controlled only by spring rate and mass. One reason people think the rear gets rougher when they raise it is because of the increased pressure in the bags, but it's really due to the angle of attack of the leading arm. If any of you have ridden in the back or tried to pee while someone else is driving, you will realize that the ride in the rear of a GMC is not very good at all--much worse than the front. The reason some high end vehicles use air suspension is to reduce noise transmissibilty due to metal in the system--we are talking frequencies of 1000hz. Ride rate is ride rate whether you get it from air bags, leaf springs or coil springs. Darn--that wore me out 
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] 1-ton installation - TB [message #153638 is a reply to message #153575] |
Mon, 19 December 2011 22:16 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Ken,
For those with front mufflers -- moving the crossmember forward by six inches may conflict. I will have to get under my coach to measure.
As you think about replacement TB and the needed spring rate -- please consider what or which would be best for those with the original front ends also.
Dennis
| Ken Henderson wrote on Mon, 19 December 2011 17:04 |
I've changed the subject to start a new thread since the old "1-ton
instatllation" was becoming too long, IMHO.
There must be something I've missed during all of these discussions,
because what I THINK I know now seems to lead to a simple solution to the
Torsion Bar problem, both for the 1-ton suspension upgrade and for
un-modified GMC's..
From the table below, it appears that the Chevrolet/GMC truck Torsion Bars
(TB's) should fit right into our A-arm sockets and our pork chops, with
just one minor problem: They're only 54" long and ours are 58-1/4" long.
But the Chevy TB's are available in a wide variety of torque ratings, are
readily available all over the country, and are, probably, still being
produced. The wonderful fact is that it apparently requires only the
drilling of 6 each 3/8" holes in the web of the GMC's chassis side rails to
allow us to fit the Chevy torsion bars!
http://www.gmfullsize.com/tech/torsion401.html
Now before I go into the simple details of that modification, someone
please tell me why Bill Hubler, to utilize Chevy torsion bars, welded in a
new socket -- I thought it was because those TB's had bigger hexes but
that's apparently not the case.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] 1-ton installation - TB [message #153642 is a reply to message #153638] |
Mon, 19 December 2011 22:24 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Dennis,
When you're checking, try 4" rather than 6" forward. I'm thinking Dale
Fromm's idea of moving the hex 2" aft into fresh socket territory, inside
the A-arm bracket, is a good idea. Take that 2" off of the 6" additional
length of the Chevy TB & wind up at 4".
The TB table should give us a clue how to find the right TB for each
situation. What we need now is a cross reference from those numbers to
applications so the junk yard can become a reasonable source.
(Assuming, of course, that any of this works out to be feasible -- that's
certainly not sure yet.)
Ken H.
On Mon, Dec 19, 2011 at 11:16 PM, Dennis Sexton wrote:
> Ken,
> For those with front mufflers -- moving the crossmember forward by six
> inches may conflict. I will have to get under my coach to measure.
>
> As you think about replacement TB and the needed spring rate -- please
> consider what or which would be best for those with the original front ends
> also.
>
> Dennis
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Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153644 is a reply to message #153575] |
Mon, 19 December 2011 22:33 |
Surbo
Messages: 213
Registered: February 2004
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Senior Member |
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| Ken Henderson wrote on Mon, 19 December 2011 17:04 |
I've changed the subject to start a new thread since the old "1-ton
instatllation" was becoming too long, IMHO.
There must be something I've missed during all of these discussions,
because what I THINK I know now seems to lead to a simple solution to the
Torsion Bar problem, both for the 1-ton suspension upgrade and for
un-modified GMC's..
From the table below, it appears that the Chevrolet/GMC truck Torsion Bars
(TB's) should fit right into our A-arm sockets and our pork chops, with
just one minor problem: They're only 54" long and ours are 58-1/4" long.
But the Chevy TB's are available in a wide variety of torque ratings, are
readily available all over the country, and are, probably, still being
produced. The wonderful fact is that it apparently requires only the
drilling of 6 each 3/8" holes in the web of the GMC's chassis side rails to
allow us to fit the Chevy torsion bars!
Ken H.
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Ken;
Moving the cross frame member forward the 4+" to accomodate the Chev truck TB will put the line bore alignment of the TB and the LCA off. The PC has some movement in the cross member so it will align, but the LCA is fixed and the TB will do more sqirming in the LCA socket during operation than it does in the OEM setup. Some of the OEM TB and LCA sockets did not have that good of alignment as it is, one of the reasons for more socket wear on some LCA sockets on some of the OEM setups than others. Alignment check of the TB and the LCA socket need to be done at normal ride height.
Bob Drewes in SESD
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| Re: [GMCnet] 1-ton installation - TB [message #153648 is a reply to message #153644] |
Mon, 19 December 2011 22:45 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Bob,
Thanks for mentioning that -- it crossed my mind once but I let it go,
thinking more of the fact that there's enough play to let it work. I
didn't give enough thought to the wear that misalignment will promote.
Perhaps someone should make a tight-fitting hex aiming device to fit into
the socket. A laser centered in the device would determine how much
misalignment really exists. Rotating the device to the 6 different
positions would inscribe a circle, the center of which would be correct,
regardless of the laser alignment accuracy. I've got a little pocket
pointer about 1/2" in diameter that would work perfectly.
What other problems can you think of? Do you know the true hex size? You
seem to have good documentation or contacts for GM stuff; how can we cross
the P/N's in the TB table to applications?
Assuming the whole thing works out, of course. :-)
Ken H.
On Mon, Dec 19, 2011 at 11:33 PM, Bob Drewes wrote:
>
> Moving the cross frame member forward the 4+" to accomodate the Chev truck
> TB will put the line bore alignment of the TB and the LCA off. The PC has
> some movement in the cross member so it will align, but the LCA is fixed
> and the TB will do more sqirming in the LCA socket during operation than it
> does in the OEM setup. Some of the OEM TB and LCA sockets did not have that
> good of alignment as it is, one of the reasons for more socket wear on some
> LCA sockets on some of the OEM setups than others. Alignment check of the
> TB and the LCA socket need to be done at normal ride height.
>
> Bob Drewes in SESD
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] 1-ton installation - TB [message #153785 is a reply to message #153642] |
Tue, 20 December 2011 17:54 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Ken et al,
As on my 73, 23 ft coach.
Here is a photo of the torsion bar crossmember in relation to the OEM exhaust. Only about 3 1/2 inches available to move the crossmember forward with this system.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=41893&title=gmc-torsion-bar-and-lca-008&cat=5975
The pork chop is approx 1 1/8 inch thick -- the gap in the crossmember is approx 1 1/2 inch -- so 3/8 inch wiggle room.
And here is a photo of the socket reinforcement on the lower control arm.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=41895&title=gmc-torsion-bar-and-lca-011&cat=5975
There are paper labels on the torsion bar -- but I did not have the coach high enough to access and read any part number.
Dennis
| Ken Henderson wrote on Mon, 19 December 2011 22:24 |
Dennis,
When you're checking, try 4" rather than 6" forward. I'm thinking Dale
Fromm's idea of moving the hex 2" aft into fresh socket territory, inside
the A-arm bracket, is a good idea. Take that 2" off of the 6" additional
length of the Chevy TB & wind up at 4".
The TB table should give us a clue how to find the right TB for each
situation. What we need now is a cross reference from those numbers to
applications so the junk yard can become a reasonable source.
(Assuming, of course, that any of this works out to be feasible -- that's
certainly not sure yet.)
Ken H.
On Mon, Dec 19, 2011 at 11:16 PM, Dennis Sexton wrote:
> Ken,
> For those with front mufflers -- moving the crossmember forward by six
> inches may conflict. I will have to get under my coach to measure.
>
> As you think about replacement TB and the needed spring rate -- please
> consider what or which would be best for those with the original front ends
> also.
>
> Dennis
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] 1-ton installation - TB [message #153806 is a reply to message #153785] |
Tue, 20 December 2011 19:42 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Dennis,
I think that would work. However, in your case especially, with a
very low mileage coach, I think I'd be more inclined to keep the OEM
bars and move the cross member to the rear that 2" to put the hex on
virgin metal inside the socket, and surrounded by the A-arm itself for
reinforcement.
That's not the last idea that's going to come down the pike though. :-)
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
On Tue, Dec 20, 2011 at 6:54 PM, Dennis Sexton <dennisfsexton@aol.com> wrote:
>
>
> Ken et al,
>
> As on my 73, 23 ft coach.
> Here is a photo of the torsion bar crossmember in relation to the OEM exhaust. Only about 3 1/2 inches available to move the crossmember forward with this system.
>
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=41893&title=gmc-torsion-bar-and-lca-008&cat=5975
>
> The pork chop is approx 1 1/8 inch thick -- the gap in the crossmember is approx 1 1/2 inch -- so 3/8 inch wiggle room.
>
> And here is a photo of the socket reinforcement on the lower control arm.
>
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=41895&title=gmc-torsion-bar-and-lca-011&cat=5975
>
> There are paper labels on the torsion bar -- but I did not have the coach high enough to access and read any part number.
>
> Dennis
>
>
> Ken Henderson wrote on Mon, 19 December 2011 22:24
>> Dennis,
>>
>> When you're checking, try 4" rather than 6" forward. Â I'm thinking Dale
>> Fromm's idea of moving the hex 2" aft into fresh socket territory, inside
>> the A-arm bracket, is a good idea. Â Take that 2" off of the 6" additional
>> length of the Chevy TB & wind up at 4".
>>
>> The TB table should give us a clue how to find the right TB for each
>> situation. Â What we need now is a cross reference from those numbers to
>> applications so the junk yard can become a reasonable source.
>>
>> (Assuming, of course, that any of this works out to be feasible -- that's
>> certainly not sure yet.)
>>
>> Ken H.
>>
>>
>> On Mon, Dec 19, 2011 at 11:16 PM, Dennis Sexton wrote:
>>
>> > Ken,
>> > For those with front mufflers -- moving the crossmember forward by six
>> > inches may conflict. I will have to get under my coach to measure.
>> >
>> > As you think about replacement TB and the needed spring rate -- please
>> > consider what or which would be best for those with the original front ends
>> > also.
>> >
>> > Dennis
>
>
> --
> Dennis S
> 73 Painted Desert 230
> Germantown, TN
> _______________________________________________
> GMCnet mailing list
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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