Home » Public Forums » GMCnet » [GMCnet] Alignment observations from SOOR
[GMCnet] Alignment observations from SOOR [message #143575] |
Fri, 16 September 2011 12:07 |
glwgmc
Messages: 1014 Registered: June 2004
Karma: 10
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We are just back from a fun and informative un-official, non-rally, SOOR event. While we did not have enough coaches there to draw any kind of general conclusions for all 8,000 of our coaches, there were some interesting observations that may be helpful to others.
First, excluding mine, only one coach that came to the SOOR non-rally was at proper ride height when it arrived. All the rest were low in front, rear or both. Being low in front throws off camber, caster and toe all three unless the coach had been specifically aligned at that lower height.
One owner took the time to restore the proper ride height. When he did, he found the camber, caster and toe returned to the nearly correct settings. It took only a bit of toe adjustment to get it spot on. With the front end low all three alignment settings were off. At proper ride height the coach was already aligned correctly. I think we might all learn something from that observation.
With Manny's expert wrenching and unlimited energy level, two owners installed the new one ton V-II front end on their coaches. One was an early 73 and the other was a 29 foot stretch made from a later model. In both cases the install went smoothly. It takes about a day for two people to do it and a day and a half to two days for one person. In both cases the ride heigh adjustment as not touched during the install. Manny has a way of using a chain and leverage to get the new lower control arms on without backing off on the torsion bar adjusters.
On the 73 coach the post-kit ride heigh was about 2" too low in front likely due to the increased leverage resulting from the wheel spacers necessary to allow the 16" Alcoas to clear the much larger brake rotors and calipers. We started with the guess that ride height would change about 1/4" per full turn of the adjuster bolt. It took four tries of adjusting the rear with air, then adjusting the front torsion bars, then driving the coach to settle the suspension, to get the ride height correct. It looks like the effective change in ride height is more like 1/8" per turn. On the later model stretch coach it came out about an inch too low in front but still took four tries to get the ride heigh correct. In both cases it is clear that the torsion bars do not respond linearly to rotation of the adjuster bolt.
Best guess for subsequent coach owners who need to adjust the ride height is the adjustment will be between 1/8" and 1/4" change in ride height for each full turn of the adjuster bolt but that decreases as you make subsequent adjustments. Remember to adjust ONLY after removing the tension on the adjuster bolt and nut with a quality torsion bar unloader tool. We had three different unloader tools available there and only the factory original tool worked well for all the users. The other two sorta worked......
Both of the one ton installs found the camber and caster to be about correct once ride height was properly set when the rear upper A arm was pushed all the way back and the front arm was centered in the slot. On the 73 the owner did have to readjust the front upper A arm cam on one side by 1/8 turn to get camber and caster the same as the other side. In both cases toe did need to be adjusted to get to zero total toe with the steering box and wheel centered.
From my own experience and from what we learned here at SOOR I remain convinced that getting our coaches to proper ride height is the singularly most important thing you can do to improve the handling of your coach. Following that, mounting proper fabric side wall radial ply tires on radial rated rims and inflating the tires to the proper pressure for the weight carried is way more important for safe driving than anything else. If you have an ill handling coach, do these things first, before you start swapping components so you have a proper base line. Then set total toe to zero and see how your coach drives. If you still feel like you are all over the road, then you will know you have worn out A arm bushings, ball joints, tie rod ends, transfer lever pivots and/or steering components. But, once your coach is at the correct ride height and you have the right tires properly inflated (which will be about 60 to 65 psi front and 55 to 60 psi rear on most 26 footers) and you
set total toe to zero, you may be quite surprised at how well your coach drives right now.
On the SOOR coaches we checked we found several had at least one bent rear bogie arm even though tire wear did not seem excessive. Most had the proper rear camber.
The alignment kit worked well and the users reported no problems in getting accurate measurements or in understanding the step-by-step instructions. So, over the weekend I will publish release version 1.0 that you can download for free. It will be on the GMC page of my web site http://jerrywork.com and can be posted on any GMC related web site with proper attribution. It is a .pdf file that includes information on why even competent professional alignment shops may struggle to properly align our GMC motor coaches, what you need to check to see if the job was done correctly or not, step-by-step instructions on how to use the inexpensive alignment kit I developed, and instructions on how you can build one to donate to your GMC club if you prefer to build rather than buy. Hope this helps.
Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR
Visitors always welcome!
glwork@mac.com
http://jerrywork.com
541-592-5360
Founder of the Southern Oregon Guild
www.southernoregonguild.org
Member of the Siskiyou Guild
www.siskiyouguild.org
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Jerry & Sharon Work
78 Royale
Kerby, OR
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Re: [GMCnet] Alignment observations from SOOR [message #143582 is a reply to message #143575] |
Fri, 16 September 2011 12:50 |
James Hupy
Messages: 6806 Registered: May 2010
Karma: -62
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Senior Member |
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Good job Jerry. I also atttended SOOR 2011. My coach got left forlonely in
Salem due to an ailing transmission, which is now in the process of
replacement along with a 3:70 Final drive. Manny T worked like a rented mule
and each coach owner whose coach was worked on also participated in the
repairs. Altogether a enthusiastic bunch of GMCers. The Work Alignment
Fixture kit works as well as any Hunter or Snap On unit that you will find
in a commercial alignment shop. His fixtures are accurately made, stay put
while precision measurements are taken, and are simple enough for nearly all
GMCers to use. I concur that each GMC organization should have one of his
kits to use by groups of members. Between ride height adjustments, short
settling drives, further adjustments, more settling drives, it takes the
better part of 4 hours to correct ride height and to adjust camber, caster,
toe, and rear wheel alignment on a GMC. I would defy anyone that is not
familiar with a GMC to do it any quicker than that. It is not hard work, but
it is precision work that once accomplished should serve the owner well for
a very long time, unless they make a habit of striking curbs with their
suspensions. A great big thanks to the Ladies of SOOR for their Crabbing,
Clamming, Mushrooming, Turkey Frying, culinary expertise. Our happy hours
were a slight bit longer than an hour, but much GMCing got done. All pets
that escaped were returned to their rightfull places due to the owners
willingness to slide on their butts on some very steep sidehills. Be sure
and download Jerry Work's Alignment instructions, and give serious thought
to club purchase of one of his alignment kits. The cost only covers his
expenses, I am sure. Thanks again to all.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Fri, Sep 16, 2011 at 10:07 AM, Work Jerry <glwork@mac.com> wrote:
> We are just back from a fun and informative un-official, non-rally, SOOR
> event. While we did not have enough coaches there to draw any kind of
> general conclusions for all 8,000 of our coaches, there were some
> interesting observations that may be helpful to others.
>
> First, excluding mine, only one coach that came to the SOOR non-rally was
> at proper ride height when it arrived. All the rest were low in front, rear
> or both. Being low in front throws off camber, caster and toe all three
> unless the coach had been specifically aligned at that lower height.
>
> One owner took the time to restore the proper ride height. When he did, he
> found the camber, caster and toe returned to the nearly correct settings.
> It took only a bit of toe adjustment to get it spot on. With the front end
> low all three alignment settings were off. At proper ride height the coach
> was already aligned correctly. I think we might all learn something from
> that observation.
>
> With Manny's expert wrenching and unlimited energy level, two owners
> installed the new one ton V-II front end on their coaches. One was an early
> 73 and the other was a 29 foot stretch made from a later model. In both
> cases the install went smoothly. It takes about a day for two people to do
> it and a day and a half to two days for one person. In both cases the ride
> heigh adjustment as not touched during the install. Manny has a way of
> using a chain and leverage to get the new lower control arms on without
> backing off on the torsion bar adjusters.
>
> On the 73 coach the post-kit ride heigh was about 2" too low in front
> likely due to the increased leverage resulting from the wheel spacers
> necessary to allow the 16" Alcoas to clear the much larger brake rotors and
> calipers. We started with the guess that ride height would change about
> 1/4" per full turn of the adjuster bolt. It took four tries of adjusting
> the rear with air, then adjusting the front torsion bars, then driving the
> coach to settle the suspension, to get the ride height correct. It looks
> like the effective change in ride height is more like 1/8" per turn. On the
> later model stretch coach it came out about an inch too low in front but
> still took four tries to get the ride heigh correct. In both cases it is
> clear that the torsion bars do not respond linearly to rotation of the
> adjuster bolt.
>
> Best guess for subsequent coach owners who need to adjust the ride height
> is the adjustment will be between 1/8" and 1/4" change in ride height for
> each full turn of the adjuster bolt but that decreases as you make
> subsequent adjustments. Remember to adjust ONLY after removing the tension
> on the adjuster bolt and nut with a quality torsion bar unloader tool. We
> had three different unloader tools available there and only the factory
> original tool worked well for all the users. The other two sorta
> worked......
>
> Both of the one ton installs found the camber and caster to be about
> correct once ride height was properly set when the rear upper A arm was
> pushed all the way back and the front arm was centered in the slot. On the
> 73 the owner did have to readjust the front upper A arm cam on one side by
> 1/8 turn to get camber and caster the same as the other side. In both cases
> toe did need to be adjusted to get to zero total toe with the steering box
> and wheel centered.
>
> From my own experience and from what we learned here at SOOR I remain
> convinced that getting our coaches to proper ride height is the singularly
> most important thing you can do to improve the handling of your coach.
> Following that, mounting proper fabric side wall radial ply tires on radial
> rated rims and inflating the tires to the proper pressure for the weight
> carried is way more important for safe driving than anything else. If you
> have an ill handling coach, do these things first, before you start swapping
> components so you have a proper base line. Then set total toe to zero and
> see how your coach drives. If you still feel like you are all over the
> road, then you will know you have worn out A arm bushings, ball joints, tie
> rod ends, transfer lever pivots and/or steering components. But, once your
> coach is at the correct ride height and you have the right tires properly
> inflated (which will be about 60 to 65 psi front and 55 to 60 psi rear on
> most 26 footers) and you
> set total toe to zero, you may be quite surprised at how well your coach
> drives right now.
>
> On the SOOR coaches we checked we found several had at least one bent rear
> bogie arm even though tire wear did not seem excessive. Most had the proper
> rear camber.
>
> The alignment kit worked well and the users reported no problems in getting
> accurate measurements or in understanding the step-by-step instructions.
> So, over the weekend I will publish release version 1.0 that you can
> download for free. It will be on the GMC page of my web site
> http://jerrywork.com and can be posted on any GMC related web site with
> proper attribution. It is a .pdf file that includes information on why even
> competent professional alignment shops may struggle to properly align our
> GMC motor coaches, what you need to check to see if the job was done
> correctly or not, step-by-step instructions on how to use the inexpensive
> alignment kit I developed, and instructions on how you can build one to
> donate to your GMC club if you prefer to build rather than buy. Hope this
> helps.
>
> Jerry
>
>
> Jerry Work
> The Dovetail Joint
> Fine furniture designed and hand crafted in the 1907 former Masonic Temple
> building in historic Kerby, OR
> Visitors always welcome!
> glwork@mac.com
> http://jerrywork.com
> 541-592-5360
>
> Founder of the Southern Oregon Guild
> www.southernoregonguild.org
> Member of the Siskiyou Guild
> www.siskiyouguild.org
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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Re: [GMCnet] Alignment observations from SOOR [message #143631 is a reply to message #143575] |
Sat, 17 September 2011 07:59 |
gbarrow2
Messages: 765 Registered: February 2004 Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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Senior Member |
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SOOR 2011 was the best kept secret on the GMCnet.
I asked last April if any one was planning one this year and the answer was NO.
So I went up to Roy, Washington for Terry Skinner's Pasture Rally.
Had a great time. Thanks Terry.
I check the net frequently and never saw any info about SOOR.
How did you guys plan a rally and keep it a secret?
Would like to have been there. But since I'm now on the road in Virginia probably couldn't have made it.
Maybe next time.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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Re: [GMCnet] Alignment observations from SOOR [message #143658 is a reply to message #143639] |
Sat, 17 September 2011 16:45 |
Gary Berry
Messages: 1002 Registered: May 2005
Karma: -1
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Senior Member |
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Hey Dan;
Your spot was great and hopefully you can get it back at the next
SOOR. When I started out on my 16 day trip, I wasn't expecting to have
a 1-ton kit in the coach when I got back home. At the 49er Lost Coast
Rally, Manny surprised me and told me that he had brought a kit for me
if I wanted it, and that we could install it at the SOOR. I mean, what
could I say except YES! Then when we got to the SOOR, Jerry Work said
he would help me do the alignment with his FANTASTIC alignment tool. I
mean, what could I say but YES! After 2 days of working my butt off
with Manny, GeneF, and JerryW I now know all about the 1-Ton kit, the
new Alignment tool, and how to use the Unloader tool (I mean I REALLY
know now how to use that tool (for the ride height adjustments)). The
new frontend is working great and I could really tell the difference
in the more precise steering and the better braking (thanks to those
huge rotors). I also hadn't done the bearings on the coach since I
bought it which was 48k miles ago, and now I don't have to worry about
them ever again. I did make it up my driveway without any problems
with hopping or wobbling, so I'm loving the new frontend. So I gotta
thank the Wheelers for holding the SOOR, then Manny for bringing and
installing the 1-Ton kit, then to Jerry Work for the alignment help.
--
Gary and Diana Berry
73 CL Stretch in Wa.
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Re: [GMCnet] Alignment observations from SOOR [message #143681 is a reply to message #143679] |
Sat, 17 September 2011 20:40 |
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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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Dan,
She will when one of them fail!
Regards,
Rob M.
-----Original Message-----
From: Dan Gregg
Mine got traded in on the new stuff. I do not keep anything I don't need. Of course "need" has a different meaning to me than it
does to Teri. :lol: She may not understand whey we carry the big rebuilt starter and alternator in the coach.
dan
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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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