Home » Public Forums » GMCnet » [GMCnet] Interesting comparison. 1 ton to original suspension.
| [GMCnet] Interesting comparison. 1 ton to original suspension. [message #250976] |
Thu, 29 May 2014 23:58  |
BobDunahugh
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
|
Senior Member |
|
|
Got my original 78 GMC aligned today. Had the 78 GMC that I put the 1 ton in last year both together. Had some road race friends over tonight. Good drivers can read the car, and track by the feel of how the car handles. The key to winning is having the ability to feel each tire. Can tell if each spring, shock, and other suspension component is performing to the track surface at that temperature. They can even give you a good idea of how much fuel that's in the tank by feel. I'm fairly good at feeling the car, and track. But not good enough to win all the time. So with these kinds of drivers at hand. I thought a comparison might be fun. I told them to drive each GMC the same 5 mile route at the same speeds. I told them nothing of the differences between each coach. Both 78 GMC's. I just said that I wanted feedback on how each GMC handled. Or if they handled the same. Remember. This wasn't very scientific. But with very good drivers. Every one of them liked, and were imp
ressed with the original GMC's handling for a vehicle that big. Statements on the one with the 1 ton conversion. 4 of the 5 drivers felt that there were some suspension geometry issues. 3 didn't like the handling at all. The other 2 said that they felt uncomfortable with it. And felt that they wouldn't want to travel a long distance in it. You must remember that these drivers are trained to be very very sensitive to the handling of what they're driving. And having two GMC's to compare with in 15 minutes. Can make things stand out more. I'm NOT saying that the 1 ton conversion is bad. It's just some observations. Last year when I installed that 1 ton kit. I made a model of it. Then a model of the original. Yes. I did have some geometry issues with the 1 ton kit. Sorry. I'm a suspension nut. GM should have put a ground finish in the bearing bore. That was the weakest link. After all. It's worked for 41 years. Not too bad. As for tracking. A lot of vehicles don't have the same
track front to rear. For me after making the models. I'm sticking with GM's idea. Please don't shoot the messenger. ( GRIN ) I just thought it was interesting. Bob Dunahugh
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #250993 is a reply to message #250976] |
Fri, 30 May 2014 04:54  |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
The problem is. There are no new parts for the oem system.
http://gmcmotorhome.info/front.html
Erf
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and -------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
> On May 29, 2014, at 9:58 PM, Bob Dunahugh wrote:
>
> Got my original 78 GMC aligned today. Had the 78 GMC that I put the 1 ton in last year both together. Had some road race friends over tonight. Good drivers can read the car, and track by the feel of how the car handles. The key to winning is having the ability to feel each tire. Can tell if each spring, shock, and other suspension component is performing to the track surface at that temperature. They can even give you a good idea of how much fuel that's in the tank by feel. I'm fairly good at feeling the car, and track. But not good enough to win all the time. So with these kinds of drivers at hand. I thought a comparison might be fun. I told them to drive each GMC the same 5 mile route at the same speeds. I told them nothing of the differences between each coach. Both 78 GMC's. I just said that I wanted feedback on how each GMC handled. Or if they handled the same. Remember. This wasn't very scientific. But with very good drivers. Every one of them liked, and were imp
> ressed with the original GMC's handling for a vehicle that big. Statements on the one with the 1 ton conversion. 4 of the 5 drivers felt that there were some suspension geometry issues. 3 didn't like the handling at all. The other 2 said that they felt uncomfortable with it. And felt that they wouldn't want to travel a long distance in it. You must remember that these drivers are trained to be very very sensitive to the handling of what they're driving. And having two GMC's to compare with in 15 minutes. Can make things stand out more. I'm NOT saying that the 1 ton conversion is bad. It's just some observations. Last year when I installed that 1 ton kit. I made a model of it. Then a model of the original. Yes. I did have some geometry issues with the 1 ton kit. Sorry. I'm a suspension nut. GM should have put a ground finish in the bearing bore. That was the weakest link. After all. It's worked for 41 years. Not too bad. As for tracking. A lot of vehicles don't have the same
> track front to rear. For me after making the models. I'm sticking with GM's idea. Please don't shoot the messenger. ( GRIN ) I just thought it was interesting. Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251001 is a reply to message #250993] |
Fri, 30 May 2014 08:47 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
|
Senior Member |
|
|
Bob,
thats really really interesting!
I love suspension geometry discussions.
I was one of the first people to put a Rack and pinion into a C3 Corvette and spent hours on the roll steer issue.
Can you describe what your issues are with the 1 ton?
Thanks
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
|
|
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251007 is a reply to message #251004] |
Fri, 30 May 2014 09:30 |
Keith V
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
|
Senior Member |
|
|
James Hupy wrote on Fri, 30 May 2014 09:05Keith, depends upon who is answering the query. There are only two people
involved with the 1 ton project who really know their stuff. IMHO.
JIM hupy
On May 30, 2014 7:48 AM, "Keith V" wrote:
Personally, I think if they really knew their stuff there wouldn't be issues with it would there?
I know there are benefits to it, mainly mechanical, but I'm hearing the geometry isn't right. Thats a different issue.
Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251009 is a reply to message #250976] |
Fri, 30 May 2014 09:34 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Bob,
It interesting to hear professional drivers' impressions, especially
between two "right up to snuff" coaches. I wish they'd had a chance at
some slightly less well maintained ones.
While I'm no professional by any stretch of the imagination, I have been
driving, around a lot of the world, for 65 years. During about 15,000
miles (probably about as many as anyone so far) I've found the 1-Ton to be
a significant improvement. My coach has always steered well, been willing
to take any curve much faster than I've been, and had no adverse tire wear
problems. The 1-Ton makes it even more sure-footed, without having shown
me any detrimental effects. I agree that the camber change (and probably
concurrent toe change) is not ideal, but it has, thus far, not caused any
problems.
When the benefits of the improved bearings and brakes are considered, I
think it's a very important improvement. If there does prove to be
increased front tire wear from the geometry errors, I'll be willing to
rotate tires more often. I'm sure I'll still be replacing tires based on
age, not tread condition.
Just another input for those on the fence.
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI & EBL,
Manny Brakes & 1-Ton, etc., etc.
www.gmcwipersetc.com
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251011 is a reply to message #250976] |
Fri, 30 May 2014 09:47 |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
|
Senior Member |
|
|
Isn't the issue simply because the 1ton was modified to use the original upper control arm mounts which are not in the same 'place' as they are in the GM 1 ton vehicles? This causes geometry to change as the suspension swings through it's arc.
Having just installed a Manny 1 ton, I can say that imo, for THE WAY I DRIVE, it is a better driving experience!
THE WAY I DRIVE is a key thing. I don't flog it down curves, I drive more or less in a straight line or make gentle turns because I have a coach full of things that will fall or slide off if I got enthusiastic about it. I doubt seriously I could tell much improvement if I drove a totally "correct geometry" suspension THE WAY I DRIVE but that's just me.
If I want to drive enthusiastically, I'll drive the roadster.
All that aside, relocating the control arm mounting points ain't no big thing. It's just welding once you know where things should be. But it's just not worth it imo.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
|
|
|
|
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251015 is a reply to message #251007] |
Fri, 30 May 2014 10:38 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
Covered 2. Years ago. Review old emails
FREE WIFI @ Mickey D
On May 30, 2014, at 7:30 AM, Keith V wrote:
> James Hupy wrote on Fri, 30 May 2014 09:05
>> Keith, depends upon who is answering the query. There are only two people
>> involved with the 1 ton project who really know their stuff. IMHO.
>> JIM hupy
>> On May 30, 2014 7:48 AM, "Keith V" wrote:
>
>
> Personally, I think if they really knew their stuff there wouldn't be issues with it would there?
>
> I know there are benefits to it, mainly mechanical, but I'm hearing the geometry isn't right. Thats a different issue.
>
>
>
> --
> Keith
> 69 Vette
> 29 Dodge
> 75 Royale GMC
> Mounds View. MN
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251020 is a reply to message #251017] |
Fri, 30 May 2014 11:09 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
|
Senior Member |
|
|
A Hamilto wrote on Fri, 30 May 2014 09:58Kerry Pinkerton wrote on Fri, 30 May 2014 09:47Isn't the issue simply because the 1ton was modified to use the original upper control arm mounts which are not in the same 'place' as they are in the GM 1 ton vehicles? This causes geometry to change as the suspension swings through it's arc. ... That's half the explanation and solution. The 1-ton knuckle is 2" "bigger" than OEM. So BOTH the upper AND lower control arm mounts would need to be relocated. The uppers would need to move up an inch and the lowers would need to move down an inch.
Also, Bob didn't tell us if the OEM GMC had 2" spacers like the 1-ton. If not, then that in itself might explain what the drivers were experiencing.
What's critical for this discussion is where the front ride height is set.
Bob de Kruyff
78 Eleganza
Chandler, AZ
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251062 is a reply to message #251021] |
Fri, 30 May 2014 19:23 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
|
Senior Member |
|
|
Hr would not take my old control arms. , universal joints. , cv joints. But
I am sure glad he is there. Like Patterson
Erf
On Friday, May 30, 2014, Larry wrote:
> Mr ERFisher wrote on Fri, 30 May 2014 04:54
>> The problem is. There are no new parts for the oem system.
>> http://gmcmotorhome.info/front.html
>> Erf
>> Gene Fisher -- 74-23,77PB/ore/ca
>
> Well, most of the important parts needed for our OEM front end are now
> being re-engineered, reman'd and sold by Dave Lenzi. Install his parts for
> a
> life-time. JMHO
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251064 is a reply to message #251021] |
Fri, 30 May 2014 19:47 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
G'day,
I'm going to "quote" the late Bob Drewes, who, in my opinion was one of THE sharpest guys on the GMCnet.
Below you will find a number of statements and links to photos of a presentation of his 1 ton installation he made at the GMCMI
Convention at Shawnee, OK.
It is IMPORTANT to note that he was quite clear that he was not criticizing the modification itself or the individual that supplied
the kit. He repeated that statement a number of times through out the presentation.
"Quote"
When I got my GMC I was to busy at the steering wheel so I did a complete alignment and things improved BUT I was still too busy at
the steering wheel.
The next thing I did was to install offset bushings in the rear upper control arms and things got better BUT I was still too busy at
the steering wheel.
I then decided to install a 1 ton front end and things got better BUT I was still too busy at the steering wheel.
I decided to modify the OEM upper control arms to "correct" the change in relationship between the upper and lower control arms
caused by the ball joint mounting points changing from 9" apart to 11" apart. Things got better BUT I was still too busy at the
steering wheel.
I decided to relocate the upper control arm mounting points to put them back in the same relationship as the OEM setup. Things got
better and now I'm NOT too busy at the steering wheel.
"Unquote"
http://www.gmcmhphotos.com/photos/g6613-bob-drewes-1-ton-installation.html
I agree with Larry that installing Dave's parts will result in a front end that will outlast me! ;-)
Regards,
Rob M.
Sydney, Australia
-----Original Message-----
From: Larry
Well, most of the important parts needed for our OEM front end are now being re-engineered, reman'd and sold by Dave Lenzi. Install
his parts for a life-time. JMHO
--
Larry
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
|
|
| Re: [GMCnet] Interesting comparison. 1 ton to original suspension. [message #251069 is a reply to message #251062] |
Fri, 30 May 2014 21:18 |
|
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Gene,
To keep readers from being confused I offer the following:
For the front suspension / steering Dave Lenzi rebuilds hubs, knuckle, steering boxes, idler arms, and relay levers.
http://www.bdub.net/lenzi/index.html
Steve Ferguson does the OEM control arms which are sold by JimK.
http://www.appliedgmc.com/prod.itml/icOid/647
GMC OEM Outer CV joints are rebuilt by Constant Velocity of Ocala: http://www.cvaxles.com/ However, you may have to get them from
JimB or JimK.
I have no idea where you can get rebuilt inner CV joints.
Regards,
Rob M.
-----Original Message-----
From: gene Fisher
He would not take my old control arms, universal joints, cv joints. But I am sure glad he is there. Like Patterson
Erf
On Friday, May 30, 2014, Larry wrote:
>
> Well, most of the important parts needed for our OEM front end are now
> being re-engineered, reman'd and sold by Dave Lenzi. Install his parts for
> a life-time. JMHO
> --
> Larry
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
Goto Forum:
Current Time: Tue Oct 01 09:37:36 CDT 2024
Total time taken to generate the page: 0.02389 seconds
|
GMCforum
Search
Help
Register
Login
Home
