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[GMCnet] Ride height [message #345741] Thu, 25 July 2019 20:26 Go to next message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
Karma: 10
Senior Member
Before getting worried about accuracy, look at the factory error band. It is wider on the control device (ride height sensor) than it is on the device being controlled (ride height). Hmmm

Jerry Work
Kerby, OR
———///
Message: 3
Date: Thu, 25 Jul 2019 20:25:45 +0000
From: Keith V
To: Rob via Gmclist
Subject: Re: [GMCnet] Ride height
Message-ID:


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Rob,
How accurate is fairly accurate?
————/
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Jerry & Sharon Work
78 Royale
Kerby, OR
Re: [GMCnet] Ride height [message #345742 is a reply to message #345741] Thu, 25 July 2019 20:33 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
It is either within factory allowable tolerances, or, it is not.
Jerry Work is absolutely right. The null zone is 5/8". Ride height
specs are plus or minus 1/4". Whaaat?
Jim Hupy
Salem, Or

On Thu, Jul 25, 2019, 6:26 PM Gerald Work via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Before getting worried about accuracy, look at the factory error band. It
> is wider on the control device (ride height sensor) than it is on the
> device being controlled (ride height). Hmmm
>
> Jerry Work
> Kerby, OR
> ———///
> Message: 3
> Date: Thu, 25 Jul 2019 20:25:45 +0000
> From: Keith V
> To: Rob via Gmclist
> Subject: Re: [GMCnet] Ride height
> Message-ID:
> DM5PR02MB277979008E70CA210C4DDD2CA4C10@DM5PR02MB2779.namprd02.prod.outlook.com
>>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Rob,
> How accurate is fairly accurate?
> ————/
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Re: [GMCnet] Ride height [message #345756 is a reply to message #345741] Fri, 26 July 2019 04:22 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
On the rears I always set them and drive it for 8 miles on 2 lane county roads and come back on 4 lane divided highway to where it settles down. Then I readjust and drive it again. Usually it does not need a 3rd adjustment.

The fronts are a different issue. We have found 1/4" off transfers 125 pounds between the front wheels (front left to right). So I set and block the rear wheels at exactly correct, then adjust the fronts by weight (maximum 100 pounds difference). Then measure the front heights and they almost always equal. So we adjust the front as a pair to get the correct height.

The problem with this coach design is the rears are a dynamic adjustment while the fronts are static. Unlike a car or truck with torsion bar suspension, is a strange relationship.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] Ride height [message #345758 is a reply to message #345756] Fri, 26 July 2019 08:33 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Ken,
Know that Friont present a problem as lot or the suspension parts will
cause severe histerrisid when taking height measurements .
Also the geometry is such that the wheels will also add to this .
We use the swivel plate that is built in on our lift to lessen that effect
and bounce it several times but we still need to drive it to where it
settles.

On Fri, Jul 26, 2019 at 2:23 AM Ken Burton via Gmclist <
gmclist@list.gmcnet.org> wrote:

> On the rears I always set them and drive it for 8 miles on 2 lane county
> roads and come back on 4 lane divided highway to where it settles down. Then
> I readjust and drive it again. Usually it does not need a 3rd adjustment.
>
> The fronts are a different issue. We have found 1/4" off transfers 125
> pounds between the front wheels (front left to right). So I set and block
> the rear wheels at exactly correct, then adjust the fronts by weight
> (maximum 100 pounds difference). Then measure the front heights and they
> almost
> always equal. So we adjust the front as a pair to get the correct height.
>
> The problem with this coach design is the rears are a dynamic adjustment
> while the fronts are static. Unlike a car or truck with torsion bar
> suspension, is a strange relationship.
> --
> Ken Burton - N9KB
> 76 Palm Beach
> Hebron, Indiana
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Jim Kanomata
Applied/GMC, Newark,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] Ride height [message #345763 is a reply to message #345758] Fri, 26 July 2019 09:30 Go to previous message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Yesterday, I was thinking about weight and balance while I was driving from
Petaluma, California to our home in Salem, Oregon. A distance of 597 miles.
Elapsed time? About 11 hours. Take stops every 2 hours for toilet needs, a
gas stop in Ashland, Or. and a 20 minute lunch break at the Weed, Ca
airport rest area, and you can tell that no grass was growing under my
tires. We drove through the summit of the Siskiyou's and lake Shasta, and
three lesser known summits all with 6% gradients both up and down with
sweeping right and left high speed curves posted at 50 mph, which I took at
70 plus. I was driving my 2006 Chevrolet Trailblazer 4 x 4.
In the back, I had a complete Manny T. 1 ton front end, a stripped TM
425 Transmission, 2 ViAir 480 c compressors, all our clothes for a week
stay, Oh yes, a number of bottles of lower cost (than Oregon) liquor, and
several bottles of hand made premium Merlot and Cabernet wine by some
friends in Calistoga. Didn't weigh all that stuff, rough guesstimate is
near 500 pounds. All positioned behind the rear wheels, and above wheel
centerline.
Not conducive to crisp handling, to say the least. Talk about the
tail wagging the dog!
That brings us to weight and balance for travel. Kinda like rigging a ship
for weather. Some of you have experience in that.
What's your point, you might ask. Well, my Chev 4 x 4 ain't no race
car, and neither is a GMC MOTORHOME. Best you can hope for is to get them
to go straight down the road, neither oversteering (pushing) in the sharp
curves, nor understeering, no bump steer in the rough stuff, and minimum
amount of rut wander and wind push. That won't happen if you are the least
bit sloppy in the joints and bushings. Keep it all in as new condition as
you can, and drive them within human and mechanical limits. Best it is
likely to get.
Jim Hupy
Salem, Or



On Fri, Jul 26, 2019, 6:34 AM Jim Kanomata via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Ken,
> Know that Friont present a problem as lot or the suspension parts will
> cause severe histerrisid when taking height measurements .
> Also the geometry is such that the wheels will also add to this .
> We use the swivel plate that is built in on our lift to lessen that effect
> and bounce it several times but we still need to drive it to where it
> settles.
>
> On Fri, Jul 26, 2019 at 2:23 AM Ken Burton via Gmclist gmclist@list.gmcnet.org> wrote:
>
>> On the rears I always set them and drive it for 8 miles on 2 lane county
>> roads and come back on 4 lane divided highway to where it settles down.
> Then
>> I readjust and drive it again. Usually it does not need a 3rd adjustment.
>>
>> The fronts are a different issue. We have found 1/4" off transfers 125
>> pounds between the front wheels (front left to right). So I set and
> block
>> the rear wheels at exactly correct, then adjust the fronts by weight
>> (maximum 100 pounds difference). Then measure the front heights and they
>> almost
>> always equal. So we adjust the front as a pair to get the correct
> height.
>>
>> The problem with this coach design is the rears are a dynamic adjustment
>> while the fronts are static. Unlike a car or truck with torsion bar
>> suspension, is a strange relationship.
>> --
>> Ken Burton - N9KB
>> 76 Palm Beach
>> Hebron, Indiana
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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