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front suspension check [message #65270] Sun, 22 November 2009 08:51 Go to next message
tgeiger is currently offline  tgeiger   United States
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Registered: February 2006
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I'm located in KC and was wondering if there is anyone around this area that could check and or rebuild my front end suspension and also look at my steering shaft?? Things might be fine with it, but I would like to get it looked at by someone that knows about these.

Tom Geiger 76 Eleganza II KCMO
Re: front suspension check [message #65285 is a reply to message #65270] Sun, 22 November 2009 11:53 Go to previous messageGo to next message
rgleas is currently offline  rgleas   United States
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Location: Tulsa, Ok.
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I did this on my coach. I went through it in an orderly fashion. I did add the heavier sway bars and wheel spacers. Now it handles quite nice.

Everyone is worn differently so each one needs different parts.Most coaches have hade some changes made to them which change handling. One last thought is that the rear suspension has to be working correctly in order to adjust the front end and have the adjustments hold. The backend changes the geomerty of the front end.
Re: [GMCnet] front suspension check [message #65302 is a reply to message #65285] Sun, 22 November 2009 15:03 Go to previous messageGo to next message
Gary Casey is currently offline  Gary Casey   United States
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What is it about the "back end" that changes the geometry of the front end?
Gary


I did this on my coach. I went through it in an orderly fashion. I did add the heavier sway bars and wheel spacers. Now it handles quite nice.

Everyone is worn differently so each one needs different parts.Most coaches have hade some changes made to them which change handling. One last thought is that the rear suspension has to be working correctly in order to adjust the front end and have the adjustments hold. The backend changes the geomerty of the front end.
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Re: front suspension check [message #65309 is a reply to message #65270] Sun, 22 November 2009 16:48 Go to previous messageGo to next message
rgleas is currently offline  rgleas   United States
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A change in height of the rear even if they are equal will change the castor and camber in the front. This occurs due to the shifting of weight and the change in suspension angles. If the height in the rear changes from side to side it has the oppsite effect on the opposite corner.
Re: [GMCnet] front suspension check [message #65314 is a reply to message #65309] Sun, 22 November 2009 17:49 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
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Location: Belmont, CA
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Tom,
You should at least enroll in GMC International.
This will get you list of members all over the country and gives you a
chance to meet some in your area.
If more people on the net would do so, I'm positive that this can help
everybody . Lot of the people do not get on the net or on the
computer.
It only costs $30/year.
Being on the list of GMC International does not brand you as a joiner.
I'm always surprised to find that there is an owner close by that has
become good friend.






On Sun, Nov 22, 2009 at 2:48 PM, Roger P. Gleason <rgleas@peoplepc.com> wrote:
>
>
> A change in height of the rear even if they are equal will change the castor and camber in the front. This occurs due to the shifting of weight and the change in suspension angles. If the height in the rear changes from side to side it has the oppsite effect on the opposite corner.
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] front suspension check [message #65325 is a reply to message #65314] Sun, 22 November 2009 19:49 Go to previous messageGo to next message
tgeiger is currently offline  tgeiger   United States
Messages: 518
Registered: February 2006
Location: kansas city
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Hey, thanks for the advice. I'll check into joining right away.
Don't know for sure weather the mechanical shops around here even though they are very capable arn't familiar with the gmc. So I'll check into this.

Thanks Jim


Tom Geiger 76 Eleganza II KCMO
Re: [GMCnet] front suspension check [message #65334 is a reply to message #65309] Sun, 22 November 2009 20:56 Go to previous messageGo to next message
Gary Casey is currently offline  Gary Casey   United States
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Registered: September 2009
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Good point about weight balancing - I don't know any accurate way to detect an imbalance (wracking) except by measuring the weight on all 4 corners. But what is the height of the CG? To take a wild guess, 30 inches? If that is the CG and the wheelbase is 140 inches, a 1 inch change in height at the rear will move the CG by .003 inches. If the front weighed 3,000 pounds it would now weigh about .1 pound more (very rough approximation). Changing the rake angle just doesn't move the CG enough to think about. Changing the height at the rear by 1 inch will change the castor angle about 0.4 degrees. Is that a lot or not much? I don't know. The change in camber, by looking at the geometry, would be miniscule - probably less than 0.01 degree. Certainly if the coach is not level, the camber angles will change accordingly. If the coach normally lists 1 degree to the right should the camber angles be adjusted back to normal or should the list be
corrected? I suspect the cause of the list should first be investigated and then if it can't be corrected the camber angles should be adjusted accordingly. But in our vehicles the loading on each wheel can be adjusted individually, so there should be no reason for an uncorrectable list - right? Is the pressure in the air bags a good measure of weight? I know that when the pressure comes up in mine the right side lifts before the left. I'm tempted to put a pressure gage on each air bag in order to diagnose weight distribution. Worth it? I don't know. Note that I have more questions than answers :-)
Gary




A change in height of the rear even if they are equal will change the castor and camber in the front. This occurs due to the shifting of weight and the change in suspension angles. If the height in the rear changes from side to side it has the oppsite effect on the opposite corner.
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Re: front suspension check [message #65340 is a reply to message #65270] Sun, 22 November 2009 21:27 Go to previous messageGo to next message
rgleas is currently offline  rgleas   United States
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With gauges on the front end than playing with level on the rear made a lot more change than that when I measured it. It also affected tow in.
Re: [GMCnet] front suspension check [message #65361 is a reply to message #65302] Mon, 23 November 2009 07:08 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
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Just watch a dogs head when he wags his tail. Any changes in the rear
has an effect on something in the front. A good f'rinstance is the
addition of a 4 bag setup. If you haven't done it, you cannot even
imagine the improvement in handling and straight line driving it
makes.

On Sun, Nov 22, 2009 at 2:03 PM, Gary Casey <casey.gary@yahoo.com> wrote:
> What is it about the "back end" that changes the geometry of the front end?
> Gary
>
>
> I did this on my coach. I went through it in an orderly fashion. I did add the heavier sway bars and wheel spacers. Now it handles quite nice.
>
> Everyone is worn differently so each one needs different parts.Most coaches have hade some changes made to them which change handling. One last thought is that the rear suspension has to be working correctly in order to adjust the front end and have the adjustments hold. The backend changes the geomerty of the front end.
> _______________________________________________
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> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
>
>
>
> _______________________________________________
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> 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] front suspension check [message #65364 is a reply to message #65285] Mon, 23 November 2009 07:18 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
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Roger,
Those heavy sway bars do make a difference but the mounting tabs on
the lower control arms must be in good shape in order to handle the
extra stresses. To take it one step further, the control arms
themselves should have good bushings and make sure your shock bushings
and ball joints are in good condition too. The GMC suspension needs
to be considered in it's entirety as a system. Changing a single
element of that system will have some effect on the other components.
There's a good reason why most on this net do not advocate "bandaids"
for problems. (And I'm in no way implying that that is what you did.)
Any handling improvements should require a systematic approach.

On Sun, Nov 22, 2009 at 10:53 AM, Roger P. Gleason <rgleas@peoplepc.com> wrote:
I did this on my coach. I went through it in an orderly fashion. I
did add the heavier sway bars and wheel spacers. Now it handles quite
nice.
--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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Re: front suspension check [message #65367 is a reply to message #65270] Mon, 23 November 2009 07:39 Go to previous messageGo to next message
rgleas is currently offline  rgleas   United States
Messages: 48
Registered: May 2009
Location: Tulsa, Ok.
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Member
Anything done to the suspension to inprove handeling should only be done after all of the suspension is brought up to original condition.

The sway bars were added because I did not like being blown around by large trucks. They work as advertized. They will not fix any of the wiggle-waggle problems people complain of.

The thing to remember is that GM sold almost 13,000 of the units originally, they were advertized as driving like a car. I have yet to meet anyone that likes a car that is all over the road.

Another point is that there are a multitute of points in the suspension that will cause the same problems.

Mine will now drive straight at 80 mph if I choose to. When I brought it, it was out of control at anything above 45.

I do agree fix what broken first, then if you don't like something consider the bandaids.

Re: [GMCnet] front suspension check [message #65370 is a reply to message #65367] Mon, 23 November 2009 07:50 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
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Roger,
I like your last statement and wholeheartedly agree.
There is nothing left that I can do to the front end of my coach
that would be an improvement. Large trucks still have some effect but
not hardly as much as before. As yours did, my coach was all over the
road when I first got it. A true white knuckler to drive with half a
turn slop in the steering. It has taken a long time to get it where
it is today and most of the work was just simply taking everything
back to factory specs, with the exception of the extra caster afforded
by the offset upper bushings. Hopefully, when the new tubular lower
control arms are ready for install, the addition of a full 6 deg of
caster will make the driving the best ever. We'll see.

On Mon, Nov 23, 2009 at 6:39 AM, Roger P. Gleason <rgleas@peoplepc.com> wrote:
>
>
> Anything done to the suspension to inprove handeling should only be done after all of the suspension is brought up to original condition.
>
> The sway bars were added because I did not like being blown around by large trucks. They work as advertized. They will not fix any of the wiggle-waggle problems people complain of.
>
> The thing to remember is that GM sold almost 13,000 of the units originally, they were advertized as driving like a car. I have yet to meet anyone that likes a car that is all over the road.
>
> Another point is that there are a multitute of points in the suspension that will cause the same problems.
>
> Mine will now drive straight at 80 mph if I choose to. When I brought it, it was out of control at anything above 45.
>
> I do agree fix what broken first, then if you don't like something consider the bandaids.
>
>
> _______________________________________________
> 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: front suspension check [message #65377 is a reply to message #65270] Mon, 23 November 2009 10:30 Go to previous messageGo to next message
rgleas is currently offline  rgleas   United States
Messages: 48
Registered: May 2009
Location: Tulsa, Ok.
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Member
I made the castor correction also, It made a big change, particularly at turnpike speeds.

I generally like to stay off turnpikes and see america, not being retired it is sometimes necessary. When I do I am in a hurry and want the coach to work right.
Re: [GMCnet] front suspension check [message #65392 is a reply to message #65370] Mon, 23 November 2009 12:40 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Steve,

You were under the weather at Pueblo and so I don't know if you got to see
or hear about Dave Lenzi's modified upper control arms. I had a chat with
him about them and he noted that he was able to get over 5 degrees of
caster. The problem he ran into was that with the coach sitting still the
relief valve in the power steering pump used on the 8.1 engine popped and
the wheels wouldn't turn. Whether or not that would happen with a standard
GMC is another question. I have pictures of his engine on the front clip
before he installed it and the power steering pump does not appear to be the
same as the standard GMC. IIRC he backed down to 4.5 degrees.

I heard via the GMC grapevine that Lanny Young down in Texas installed a
pair of these control arms and that he can drive off the edge of the road
and pull right back on like he never drove off.

I'll start a new message and ask Lanny to comment.

Regards,
Rob Mueller
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Steven Ferguson
Sent: Tuesday, 24 November 2009 12:51 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] front suspension check

Roger,

Hopefully, when the new tubular lower control arms are ready for install,
the addition of a full 6 deg of caster will make the driving the best ever.
We'll see.

--
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
no expert but... [message #65444 is a reply to message #65392] Mon, 23 November 2009 22:43 Go to previous messageGo to next message
bukzin is currently offline  bukzin   United States
Messages: 840
Registered: April 2004
Location: North California
Karma: 0
Senior Member
The sense I get is you have 2 options,

do the work yourself or take it to someone

that REALLY KNOWS these rigs.



I think taking to an outfit that has done

less than 40 (or so) coaches is a mistake.



Bukzin
1977 Palm Beach

[Updated on: Mon, 23 November 2009 22:44]

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Re: [GMCnet] no expert but... [message #65465 is a reply to message #65444] Tue, 24 November 2009 06:16 Go to previous messageGo to next message
Jim Bounds is currently offline  Jim Bounds   United States
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Registered: January 2004
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Senior Member
Richard,

Not sure what your post was about but there are some that see their coach as "something to do" and for those folks propping up a GMC in the backyard assures they guy will not be bored!  There are enough things to mess with to last an entire retirement so in that situation a GMC is a great object for ones frustration.

But for those that would actually like to use their coach and have it really nice in a reasonable amount of time, if you are like me, the first time I do something takes a huge amount of time to get past the learing curve which we all know is never a cost effective project.  Quality and efficiency comes with repetition so the more times you do something the better the outcome is-- ah, but if you only have one motorhome to do work on each project you finish could have probably been done better on the next coach but --- you only have one coach!  So, having someone who has made all of the mistakes, cut up their hands sufficiently and can add to the ideas you have will usually make for a better finished product.

I do not down those that have the irresistable urge to "do it themselves", heck -- thats what I did but by this time I have at least made all of the mistakes or at least more than most folks and I can add much to the finished project.  You are right for this person and coming up with ideas and expressing what you vision is a far better part of a project to be involved with than taking on the whole enchilada.

This is the truth that when you incorporate that into your restoration plan you will realize the best outcome.  Yes, you will put more $ into the project, you are including more people into the project that will not only make the project better but hopefully will get it done quicker to let you get out on the road and use the coach sooner.  This is also a very attractive reason for including someone who can help into your project.

But, if you are the guy that is into the "chase" as much as the having, go for it man and we must recognize and support both schools of thought.

Jim Bounds
---------------------



----- Original Message ----
From: Richard <bukzin@gmail.com>
To: gmclist@temp.gmcnet.org
Sent: Mon, November 23, 2009 11:43:17 PM
Subject: [GMCnet] no expert but...



The sense I get is you have 2 options,

do the work yourself or that it to someone

that REALLY KNOWS these rigs.



I think taking to an outfit that has done

less than 40 (or so) coaches is a mistake.


--
Bukzin
1977 Palm Beach
Chico California
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Re: [GMCnet] front suspension check [message #65477 is a reply to message #65392] Tue, 24 November 2009 08:00 Go to previous messageGo to next message
Steven Ferguson is currently offline  Steven Ferguson   United States
Messages: 3447
Registered: May 2006
Karma: 0
Senior Member
Rob,
I'd like to see those pics. We're headed to Las Cruces, NM in a
couple of hours and sometime during the next week Hal Kading and I are
going to get together. He hasn't installed the oil pan on his 454 yet
so I'm going to transfer the dimensions to my 502 pan in case I get a
wild hair and want to install it in a GMC. I checked out the uppers
while in Pueblo. I do not like the price all that fine machine work
costs. Way too expensive.
I've sent Mclerran Eng. a pair of lower control arms for patterns for
tubular lowers. Hopefully, with two separate companies working on the
prototypes, we can get the best price for the community. Dave
Mclerran has done tons of this stuff before. He goes all the way back
to Dan Moon (Moone Eyes) and has done the prototype work for Belltech
etc. He has it together.
That "sore throat" problem I had at Pueblo cleared up after I started
on antibiotics. It did do permanent damage to my voice box. It aint
the same anymore.
Steve

On Mon, Nov 23, 2009 at 11:40 AM, Rob Mueller <robmueller@iinet.net.au> wrote:
> Steve,
>
> You were under the weather at Pueblo and so I don't know if you got to see
> or hear about Dave Lenzi's modified upper control arms. I had a chat with
> him about them and he noted that he was able to get over 5 degrees of
> caster. The problem he ran into was that with the coach sitting still the
> relief valve in the power steering pump used on the 8.1 engine popped and
> the wheels wouldn't turn. Whether or not that would happen with a standard
> GMC is another question. I have pictures of his engine on the front clip
> before he installed it and the power steering pump does not appear to be the
> same as the standard GMC. IIRC he backed down to 4.5 degrees.
>
> I heard via the GMC grapevine that Lanny Young down in Texas installed a
> pair of these control arms and that he can drive off the edge of the road
> and pull right back on like he never drove off.
>
> I'll start a new message and ask Lanny to comment.
>
> Regards,
> Rob Mueller
> Sydney, Australia
> AUS '75 Avion-The Blue Streak TZE365V100428
> USA '75 Avion-Double Trouble TZE365V100426
>
>
> -----Original Message-----
> From: gmclist-bounces@temp.gmcnet.org
> [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Steven Ferguson
> Sent: Tuesday, 24 November 2009 12:51 AM
> To: gmclist@temp.gmcnet.org
> Subject: Re: [GMCnet] front suspension check
>
> Roger,
>
> Hopefully, when the new tubular lower control arms are ready for install,
> the addition of a full 6 deg of caster will make the driving the best ever.
> We'll see.
>
> --
> 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] front suspension check [message #67973 is a reply to message #65270] Mon, 21 December 2009 11:49 Go to previous message
Steven Ferguson is currently offline  Steven Ferguson   United States
Messages: 3447
Registered: May 2006
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Senior Member
This is the first time I've seen this. Note the rust on the ears, and
where they attach to the body. This has been this way for a long
time. How the owner avoided catastrophic failure must be a miracle.
http://www.gmcmhphotos.com/photos/showphoto.php?photo=32016
Check 'em fellas.

--
Steve Ferguson
'76 EII
Sierra Vista, AZ
Urethane bushing source
www.bdub.net/ferguson/
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