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01-13-2016, 06:43 PM
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#1
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1 Rivet Member
2014 31' Classic
Hot Springs
, Arkansas
Join Date: Jan 2016
Posts: 16
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Pro Pride Hitch Question
We have a question as a (relative) newbie. We are pulling our 14 Classic 31 with a 15 Sierra 1500 with a 6.2L with Max trailering and a Pro Pride hitch.
The 500 mile trip home with the unit from the dealer in September felt tight with no swaying or movement when we met big rigs, but a bit of porpoising on pavement level changes.
We have spoken with Sean a couple times and he has helped a lot. The hitch had been set up for a 3/4 ton vehicle and the AS rode front low before we adjusted the truck side of the hitch up 2 holes. The AS now sits level when hitched.
On a recent 1200 mile trip, we had porpoising throughout, and experimented with the tortion bars from 8 to 8 1/2 inches. (The previous owner set them at 8 1/2.) The bars are 1400 pounds.
Any ideas on how to get the hitch balanced to our vehicle? It actually towed better with the front of the AS 4" lower than the rear, which is where the dealer set it up for us. Thanks for any suggestions.
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01-13-2016, 07:06 PM
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#2
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Rivet Master
2012 27' Flying Cloud
W
, New England
Join Date: Oct 2012
Posts: 7,402
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Hi. I can't imagine why your dealer would set up your rig so the front of the trailer was 4" nose down! If they did that - there's no telling how they installed and configured your hitch.
I have a ProPride for my 27' Flying Cloud towed by a Chevy 2500. I've had some porpoising caused by the unbalanced position of the head of the ProPride (see pic below). Even without a ruler there you can see how it was positioned crookedly. Simple adjustment with a few bolts and much better.
You may also want to experiment with height of the Weight Distribution (WD) jacks. Where are you measuring 8 to 8.5"? Mine ride best at about 6" measured from the top of the a-frame to the bottom of the risen WD jack sleeve.
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01-13-2016, 07:35 PM
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#3
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Rivet Master
2007 30' Classic
Oswego
, Illinois
Join Date: Jul 2010
Posts: 13,669
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Might be good to know your total AS weight and tongue weight too. Light tongue weight will contribute to porpoising as well. I towed my 30 classic last summer with a Sierra 1500 maxtow 6.2 and had no porpoising. With a hensley, so similar setup.
__________________
-Rich-
"If the women don't find you handsome, they should at least find you handy." - Red Green
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01-13-2016, 07:35 PM
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#4
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Rivet Master
2012 25' Flying Cloud
Battle Lake
, Minnesota
Join Date: Jun 2009
Posts: 7,714
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I wouldn't concern myself with the inches set on the w.d. screw jacks until after the trailer is level, the truck has good weight distribution, and the hitch is set up well. Then only as an easy way to repeat what you have determined to be the correct hitch/combination setup.
The weight distribution bars should angle downward toward the back, even after weight distribution is fully set. This ensures they are giving enough weight distribution, and they maintain it during their range of movement as you go over bumps in the road. This can be done by adding as many washers as you can under the big rivet in the stinger to push the drop bar down. You'll have to unbolt the drop bar to get them in. You may also have to move the drop bar up or down to get the best adjustment for weight distribution of the truck while keeping the trailer dead level.
This downward tilt also helps return the trailer to center behind the truck after turns, gives a little more stability in turns, and reduces the chance a the "Hensley Bump" in heavy braking.
I like to see the w.d. return our 1/2 ton Ram front wheel well height to it's height before the trailer is hooked up, or within an inch of it. The rear wheel well height does not concern me as much as long as it's not higher than before hookup. If the truck rear end is sitting oddly low after weight distribution, then you may have too much weight toward the back of the truck's bed, or too much weight in the front of the Airstream.
Or the truck's suspension is too weak, but that's not likely if neither truck bed or trailer front are overloaded. If they are overloaded, you will have to reduce the loads or, as some have done, get a heavier duty truck. My preference is too reduce the load if needed.
__________________
Doug and Cheryl
2012 FC RB, Michelin 16, ProPride 1400
2016 Ram 1500 Laramie Crew Cab 4X4 Ecodiesel 3.92 axles
The Truth is More Important Than the Facts
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01-13-2016, 07:38 PM
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#5
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Rivet Master
2012 25' Flying Cloud
Battle Lake
, Minnesota
Join Date: Jun 2009
Posts: 7,714
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Quote:
Originally Posted by dznf0g
Might be good to know your total AS weight and tongue weight too. Light tongue weight will contribute to porpoising as well. I towed my 30 classic last summer with a Sierra 1500 maxtow 6.2 and had no porpoising. With a hensley, so similar setup.
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Thanks Rich, that may be another possibility, not so likely with Airstreams because they tend to be heavy in front. Loading can change that.
__________________
Doug and Cheryl
2012 FC RB, Michelin 16, ProPride 1400
2016 Ram 1500 Laramie Crew Cab 4X4 Ecodiesel 3.92 axles
The Truth is More Important Than the Facts
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01-13-2016, 07:38 PM
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#6
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Rivet Master
2007 30' Classic
Oswego
, Illinois
Join Date: Jul 2010
Posts: 13,669
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Don't think the suspension is the issue I load 500 pounds in the bed with 1050 pounds receiver weight and everything is great.
__________________
-Rich-
"If the women don't find you handsome, they should at least find you handy." - Red Green
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01-14-2016, 10:26 AM
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#7
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1 Rivet Member
2011 27' FB Flying Cloud
Tulsa
, Oklahoma
Join Date: Apr 2015
Posts: 10
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Quote:
Originally Posted by SteveSueMac
Hi. I can't imagine why your dealer would set up your rig so the front of the trailer was 4" nose down! If they did that - there's no telling how they installed and configured your hitch.
I have a ProPride for my 27' Flying Cloud towed by a Chevy 2500. I've had some porpoising caused by the unbalanced position of the head of the ProPride (see pic below). Even without a ruler there you can see how it was positioned crookedly. Simple adjustment with a few bolts and much better.
You may also want to experiment with height of the Weight Distribution (WD) jacks. Where are you measuring 8 to 8.5"? Mine ride best at about 6" measured from the top of the a-frame to the bottom of the risen WD jack sleeve.
Attachment 255677
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Sean suggested 7" from the back of the hitch bars to the ground.
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01-14-2016, 11:48 AM
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#8
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Welcome Aboard....
"It actually towed better with the front of the AS 4" lower than the rear, which is where the dealer set it up for us.
4" low = tongue weight.
It toed better with TW....
Go to the CAT scales and get that puppy set up rite.
Level AS, level TV with WD set and the proper weight transferred.
Bob
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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01-14-2016, 02:35 PM
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#9
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Rivet Master
2012 23' FB International
Woodstock
, Ontario
Join Date: Aug 2014
Posts: 1,423
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My rig with a Hensley is dead level and I get porpoising on some Interstates with concrete road beds where the joints are squeezed up. I have extra leaves in the rear springs, and more weight in the truck helps but I will also be replacing rear shocks with adjustable action units now that the originals are worn. You might want to try that.
JCW
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01-14-2016, 04:38 PM
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#10
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Rivet Master
2007 30' Classic
Oswego
, Illinois
Join Date: Jul 2010
Posts: 13,669
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Quote:
Originally Posted by JCWDCW
My rig with a Hensley is dead level and I get porpoising on some Interstates with concrete road beds where the joints are squeezed up. I have extra leaves in the rear springs, and more weight in the truck helps but I will also be replacing rear shocks with adjustable action units now that the originals are worn. You might want to try that.
JCW
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On some pavements, it is what it is and you can't get rid of all of it.
__________________
-Rich-
"If the women don't find you handsome, they should at least find you handy." - Red Green
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01-14-2016, 04:46 PM
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#11
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3 Rivet Member
2016 30' Classic
Little Rock
, Arkansas
Join Date: Jan 2012
Posts: 110
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Quote:
Originally Posted by Gigi1957
We have a question as a (relative) newbie. We are pulling our 14 Classic 31 with a 15 Sierra 1500 with a 6.2L with Max trailering and a Pro Pride hitch.
The 500 mile trip home with the unit from the dealer in September felt tight with no swaying or movement when we met big rigs, but a bit of porpoising on pavement level changes.
We have spoken with Sean a couple times and he has helped a lot. The hitch had been set up for a 3/4 ton vehicle and the AS rode front low before we adjusted the truck side of the hitch up 2 holes. The AS now sits level when hitched.
On a recent 1200 mile trip, we had porpoising throughout, and experimented with the tortion bars from 8 to 8 1/2 inches. (The previous owner set them at 8 1/2.) The bars are 1400 pounds.
Any ideas on how to get the hitch balanced to our vehicle? It actually towed better with the front of the AS 4" lower than the rear, which is where the dealer set it up for us. Thanks for any suggestions.
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Recognize I have a whopping one week of experience towing a Classic ('16) using a ProPride hitch system, so take this as just data; thought it might help. Completely different TV, an F250 diesel. Would ask if you have all three 5/8"x4.5 in bolts in the stinger assembly? Also, when the stinger is in your hitch receiver, is it level? Look at the last page of the PP manual and run through the calculation to determine any drop you will need to take into account in assembling the stinger assembly. The solution to that equation will be the drop or rise needed to match the trailer (at level) with the truck (at rest without load. Also, check every single bolt in the entire assembly and be certain they are tight and tightened to the proper torque setting. We were at a rally last week and greatly benefitted from several others (three engineers!) who had PPs. Ran through the calculations, made several changes and completely changed the manner in which the trailer rode. Reduced rear end drop dramatically and eradicated porpoising. I went from worried to confident. It is a great towing system, but it is complex.
__________________
_________________________________
Boogieshoes, DH of JudyJudy; AS "Rose"
WBAC 5932Arkansas Razorbacks Unit
2016 F250 KR 6.7 4x4 CC "Tex"
Members, NTAC
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01-14-2016, 05:11 PM
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#12
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Rivet Master
1999 34' Excella
Currently Looking...
Hillsboro
, Texas
Join Date: Feb 2013
Posts: 6,408
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Consider the SCALES!! Worth it. Do it right.
Next, check the gear you have in your AS... If you don't have it "balanced" like too much "aft" of the axles, it will tend to porpoise.
Our 34' AS, "1400#" bars.. If loaded wrong, bouncy bouncy. I only crank from 5-5.5" on adjusting bars.. It runs 1/2" nose ...with all gear properly stowed and full water. Our TV is 2012 2500 Duramax 4x4 crew cab. Plenty length to minimize bounce of the AS in most situations... Even on most Louisiana roads.
__________________
Peace and Blessings..
Channing
WBCCI# 30676
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01-14-2016, 07:26 PM
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#13
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2020 Classic 33
Box Elder
, South Dakota
Join Date: Oct 2013
Posts: 1,731
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Ditto to the scales. Lookup the scale weighing process from Ron Gratz. Like this thread.
http://www.airforums.com/forums/f464...es-105930.html
Basic process to really dial things in is multiple passes on the scale. Truck/Trailer weighed at the settings you currently have, Truck/Trailer with the jacks at the bottom, Truck only. All hopefully with stuff you normally take camping, full truck fuel and water tank full or how you normally tow when camping. To get even more information do additional weights, they only cost $2, with your WD jacks from your starting point -2, -1 and +1 inches.
Throw it into the spreadsheet that is in the link that put together with Ron's information and you can better determine what is going on with the actual movement of weight to the front axle. GMC says restore 50% of the difference between the height of pavement to the bottom of the front fender well between truck only and truck with trailer attached but NO WD applied. I look at that as well as the weights (usually works out to restore 50% of weight) and then you should be dialed in.
CAT Calc Sierra 2500 Classic 5-2-15.xlsx
__________________
Gary
2020 Classic 33 Twin, 2019 Ram 3500 Longhorn, ProPride
NØVPN
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01-15-2016, 07:13 AM
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#14
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Rivet Master
1999 34' Excella
Currently Looking...
Hillsboro
, Texas
Join Date: Feb 2013
Posts: 6,408
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Oh how fast do you pull? I pull about 60.. Too fast you can develop an oscillation if roads undulate. I have had that in our 34'
Also our truck original shocks were incapable of decelerating. Had to slow under 45 to get it to stop.
Just ideas since we do not know your situation, operating speeds.. Etc.
__________________
Peace and Blessings..
Channing
WBCCI# 30676
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01-15-2016, 07:29 AM
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#15
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Rivet Master
2014 31' Classic
2015 23' International
2013 25' FB International
Apache Junction
, Arizona
Join Date: Sep 2012
Posts: 6,223
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Our dynamic changes when the fresh water moves aft into the black and gray water tanks on the Classic. I find I have to drop the height of the jacks to 5" from 5.5". Initially we had a 6" setting, but after taking 175 pounds of battery and stainless steel enclosure weight off of the tongue weight and getting rid of the original water heater and the six gallon hot water storage (which was 80 pounds less weight just behind the street side wheel well), the dynamic changed.
We are still playing with the height of the jacks. If I get them too short, we get both slight oscillations and bounce.
We had more than the provided number of washers in the adjustable hitch head, but I may need to add some more, perhaps with a longer bolt for them to ride on.
__________________
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic w/ twin beds, 50 amp service, 1000 watt solar system, Centramatics, Tuson TPMS, 12" disc brakes, 16" tires & wheels
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01-15-2016, 04:05 PM
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#16
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Wise Elder
2010 30' Classic
Vintage Kin Owner
South of the river
, Minnesota
Join Date: Dec 2009
Posts: 4,169
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Quote:
Originally Posted by dznf0g
On some pavements, it is what it is and you can't get rid of all of it.
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Rich is correct.
Up-and-down (vertical) movement of the rear of the tow vehicle is not sway and cannot be controlled by changing the hitch around. This is not a problem unique to ProPride; all hitches do it.
The root cause is an undulating pavement surface. Usually the amplitude of the pavement changes is small enough that it isn't noticeable without a trailer. The physics of it has to do with the "normal mode" or resonant frequency of the combination of the tow vehicle rear springs and the weight on them.
If the rear shock absorbers in the tow vehicle have failed, that will make the movement much worse. If they are still good, it will help somewhat to replace them with heavy duty shocks, at the expense of an overall stiffer ride.
Front shocks can also help a little.
Reduced speed can help somewhat.
__________________
To learn to see below the surface, you must adjust your altitude
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01-16-2016, 06:39 AM
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#17
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Rivet Master
2012 23' FB International
Woodstock
, Ontario
Join Date: Aug 2014
Posts: 1,423
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Quote:
Originally Posted by cwf
Oh how fast do you pull? I pull about 60.. Too fast you can develop an oscillation if roads undulate. I have had that in our 34'
Also our truck original shocks were incapable of decelerating. Had to slow under 45 to get it to stop.
Just ideas since we do not know your situation, operating speeds.. Etc.
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I have had several situations where it was impossible to stop the porpoising and others where a change in speed settled things down somewhat.
The issue is partly spring rates in the truck and the ability of shocks, but I also believe the spacing in the road joints is a more important factor. The porpoising is due to a natural frequency in the total rig. Some roads simply match the distance between the TV wheels and the Trailer in a way that sets the whole rig into a natural bounce usually referred to as sympathetic frequency. Longer rigs like tractor trailers don't (usually) have the problem.
In my worst case it didn't matter how much I slowed down; sometimes speeding up actually improves it but it will always be there if the road conditions are right!
JCW
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01-16-2016, 07:59 AM
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#18
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Rivet Master
2007 30' Classic
Oswego
, Illinois
Join Date: Jul 2010
Posts: 13,669
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Quote:
Originally Posted by JCWDCW
I have had several situations where it was impossible to stop the porpoising and others where a change in speed settled things down somewhat.
The issue is partly spring rates in the truck and the ability of shocks, but I also believe the spacing in the road joints is a more important factor. The porpoising is due to a natural frequency in the total rig. Some roads simply match the distance between the TV wheels and the Trailer in a way that sets the whole rig into a natural bounce usually referred to as sympathetic frequency. Longer rigs like tractor trailers don't (usually) have the problem.
In my worst case it didn't matter how much I slowed down; sometimes speeding up actually improves it but it will always be there if the road conditions are right!
JCW
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Yup
__________________
-Rich-
"If the women don't find you handsome, they should at least find you handy." - Red Green
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01-16-2016, 08:56 AM
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#19
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Rivet Master
2012 25' Flying Cloud
Battle Lake
, Minnesota
Join Date: Jun 2009
Posts: 7,714
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Could this be one of the reasons the Airstream Owners Manual cautions to never exceed 1,000 lbs hitch weight (similarly, amplifying any sway tendencies)?
Using their guidance of at least 10% of trailer weight, not to exceed 1,000 lbs, our hitch weight must be between 720 lbs and 1,000 lbs, for example.
__________________
Doug and Cheryl
2012 FC RB, Michelin 16, ProPride 1400
2016 Ram 1500 Laramie Crew Cab 4X4 Ecodiesel 3.92 axles
The Truth is More Important Than the Facts
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01-17-2016, 03:52 AM
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#20
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Rivet Master
2014 31' Classic
2015 23' International
2013 25' FB International
Apache Junction
, Arizona
Join Date: Sep 2012
Posts: 6,223
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We had a diesel Suburban in the mid 90s (it lived at the dealership due to exceptionally poor engine design) and were driving in Wyoming at the posted 80 mph with just two of us and some luggage in the car. The road was undulating and we were getting pounded by the suspension. Slowing to 72 mph, the frequency of the road and the long wheel base came into synch and the ride was smooth again.
That road and vehicle harmonic also comes into play when towing.
__________________
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic w/ twin beds, 50 amp service, 1000 watt solar system, Centramatics, Tuson TPMS, 12" disc brakes, 16" tires & wheels
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