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05-19-2018, 08:58 PM
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#1
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Another "How Do These Numbers Look?" WD Hitch Thread
First time using a WD Hitch, so I'm looking for some opinions on the CAT scale numbers I got today.
Unfortunately it was raining today so I did not unhitch the trailer on the scale to get the actual gross or tongue weight. For now I'm assuming the Airstream specs are close enough until I have a chance to get over to the scales again.
TV is a Toyota Tacoma:
GVWR: 5600, Gross Weight of truck 4440
GCWR: 11360, Combined Gross weight with trailer 9000
TT is a Flying Cloud 20FB
GVWR: 5000, did not get actual weight, but 4271 according to specs
Hitch is a Reese 800 lb Round Bar WD Hitch with Dual-Cam Sway Control
CAT SCALE RESULTS:
FRONT:
GAWR: 2910
No Trailer: 2520
W/ Traile: 2560
REAR:
GAWR: 3280
No Trailer: 1920
W/ Trailer: 2360
TRAILER:
GAWR: 4080
Using the Airstream trailer specs, my understanding is that the distribution of the Tongue Weight is now: Front - 40 lbs, Rear - 440 lbs, Trailer - 150
Is this correct?
My first reaction seeing the results was not enough weight is being distributed to the front, but I'm not sure.
Toyota manual states "If using a weight distribution hitch when towing, return the front axle to the same weight as before the trailer connection." The Reese manual basically says the front and rear should settle equally. Within 1/2" of each other is OK as long as the rear settles more. This is exactly what my setup is doing. Rear settles 3/4", front settles a bit more than 1/4". The Airstream owner manual calls for 1/3 of the tongue weight to be evenly distributed between the three axles.
So, of the three guidelines the Airstream is the only one calling for that much tongue weight to go to the front. Reason I'm not sure about doing that is it seems like a pickup is designed to have the majority of any load it carries be added to the rear axle.
The load capacity (not sure if that's the right term) of rear axle is 1320 lbs, while the load capacity of the front axle is only 390 lbs.
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05-19-2018, 09:40 PM
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#2
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Site Team
2017 30' International
Broomfield
, Colorado
Join Date: Apr 2009
Posts: 3,555
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Yet Another "How Does This Look?" WD Hitch Thread
Tiny load here on your TV given your gross axle weight ratings. You are + 40lbs on the front axle from unloaded weight. Your are more than 1000lbs under your rear gawr.
That’s nothing. You are good to go - don’t sweat it[emoji4]
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05-19-2018, 10:02 PM
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#3
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Rivet Master
2002 30' Classic S/O
Fleming Island
, Florida
Join Date: Nov 2013
Posts: 4,673
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wulfraat is right. If anything you have too much weight to the front. The Airstream tongue weight is for an empty trailer and at that may be optimistic. In order to know how the tongue weight is distributed, you have to know what the tongue weight is. The only way to get that while weighing is to take three weights.
1 - Two numbers: TV only Front (Steer) axle and rear (drive) axle with WD hitch and bars on the TV
2 - Three numbers: TV+TT Front, rear, and trailer axles without weight distribution engaged
3 - Three numbers: TV+TT Front, rear, and trailer axles with weight distribution engaged
Now you can add TV front and rear from weighing 1 and subtract that from TV front and rear from weighing 2. That will tell you the tongue weight. Personally I go a step further and say that the "effective" tongue weight is the difference between the TV axle weights from weighing 3 and weighing 1.
The differences in the axle weights from weighing 2 and 3 will show you how the weight is being distributed. Weighing 2 is critical for heavier trailers but your trailer is so light that it isn't really necessary, at least in my opinion.
Al
__________________
“You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO WBCCI 1322
2002 Classic 30 Slideout -S/OS #004
2013 Dodge 2500 Laramie 4x4 Megacab Cummins
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05-19-2018, 11:48 PM
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#4
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Journeyman
2016 25' International
Amherst
, Massachusetts
Join Date: Apr 2016
Posts: 956
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Toyota has really big axle ratings relative to actual vehicle weight. Tough trucks--and a real emphasis on durability from the maker.
I just switched from Toyota to Ford. "By the numbers" for GVWR the ford is rated much higher for payload... but by the axle ratings the (older, smaller) Toyota had almost 500# more capacity. Toyota is all about QDR and they do it well.
Top Gear tried to kill a Toyota in a famous string of episodes. It's worth watching. Here's the first of three parts... and part III involves quite a lot of explosives and is unsuccessful in killing the Toyota!
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05-20-2018, 06:57 AM
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#5
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Quote:
Originally Posted by Al and Missy
wulfraat is right. If anything you have too much weight to the front. The Airstream tongue weight is for an empty trailer and at that may be optimistic.
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Thanks to everyone for the info! When I bought the trailer it came with the Reese WD hitch and sway control. The round bars were for 600 lb. max tongue weight. I'm not very experienced at towing so I could be wrong, but to me those bars felt too light. Felt like there was too much rocking up and down. So I bought new bars rated 400-800 lbs figuring my 600 lb tongue weight sat right in the middle.
It does feel much more stable now, the springy up and down is gone but does not feel harsh. But, I think you are right and it is putting too much weight up front, so I will back it off one link on the WD chains and see how that feels.
All, once I get everything where it "feels" good I'll take another trip to the scales and get all the weights you described. Thanks for the help!
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05-20-2018, 10:09 AM
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#6
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Site Team
2017 30' International
Broomfield
, Colorado
Join Date: Apr 2009
Posts: 3,555
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Yet Another "How Does This Look?" WD Hitch Thread
See you are a pro now! Feel is very important. Try it out with slightly less WD applied and see how you like it. I would personally drive your setup as is if that is the best feel with regards to steering...., true you are 40 pounds more to your front axle but it’s only 40 pounds and you have good weight on the rear tires.
200lbs over on the front would be another story [emoji4]
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05-24-2018, 08:09 AM
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#7
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Vintage Kin
Fort Worth
, Texas
Join Date: Nov 2006
Posts: 8,014
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A simple way to look at it is:
A WDH restores the scaled weight value of the TV Steer Axle to the unhitched number.
That’s the starting point. It may be best, or more & less spring bar tension need also to be tested for best result.
Be sure to adjust TV tire pressure to the new condition.
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05-24-2018, 07:15 PM
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#8
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Rivet Master
2007 22' International CCD
Corona
, California
Join Date: Jul 2013
Posts: 9,180
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Yet Another "How Does This Look?" WD Hitch Thread
Now you guys understand why I’m going to powered WD jacks so I can adjust on the road easily? I can easily feel front end instability when I don’t have enough WD cranked in...
And with a light truck instability anywhere is just waiting to bite you...
That why tire pressure in the AS and TV gets checked and adjusted before heading out every day.
The whole setup is a “complete system” and needs to be thought of as such.
__________________
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.
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05-28-2018, 06:00 PM
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#9
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Quote:
Originally Posted by slowmover
A simple way to look at it is:
A WDH restores the scaled weight value of the TV Steer Axle to the unhitched number.
That’s the starting point. It may be best, or more & less spring bar tension need also to be tested for best result.
Be sure to adjust TV tire pressure to the new condition.
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That was the impression I was getting from two of the three sources of info I was using. The Toyota owners manual and the Reese hitch manual. Only one that caused confusion was the Airstream owners manual that said to transfer 33% of the tongue weight to the front axle.
Just got back from a weekend trip with the trailer. Towed from Southern RI to Ascutney Mt. in Vermont. Everything felt good. I like the new spring bars better.Thanks for the help!
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05-28-2018, 06:23 PM
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#10
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Moderator
2017 26' Flying Cloud
Alamo Heights
, Texas
Join Date: Aug 2006
Posts: 8,536
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You are likely transferring WAY more than 40 lb of tongue weight with your WD hitch. If you'd taken the 3rd standard measurement (trailer on the hitch but no WD set) you'd likely have found your front axle was well below the weight you measure without the trailer. In my case, with the trailer on the hitch and no WD set, the steer axle is 400 lb lighter than the truck alone. Having the WD set brings me within 20 lb of the no-trailer value, but I wouldn't worry about being +40 on the front axle since you're adding a great deal of weight to the rear axle and your'e within about 1.5% of the initial weight on your steer axle. If the on-road manners are good, that's probably a decent setup.
People make more of a difference than that on their steer-axle weights on a pickup by hanging a brushguard or a bike rack on the front.
__________________
— David
Zero Gravitas — 2017 Flying Cloud 26U | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill
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05-28-2018, 06:43 PM
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#11
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Rivet Master
2007 22' International CCD
Corona
, California
Join Date: Jul 2013
Posts: 9,180
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Noted the comment on “on-road manners” is a good way to point out the need to get enough WD to get the front axle back to unhitched weight or slightly more. If the front axle is significantly light, the steering will be sloppy or unsure felling, and the front end will feel like it is bouncing up and down excessively. I have referred to this as “porpoising”. My DW is the quickest indicator, as she gets carsick if we are not ‘planted and stable’ on the front end. The TV steering should feel just as positive as the unhitched condition. This is critical to maintaining control of the rig in emergency maneuvers, for one, and windy conditions as well.
I think it is the most important measurement that is being discussed...
__________________
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.
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05-29-2018, 05:44 AM
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#12
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Confused....🙃
How does the GAWR change?
Bob
🇱🇷
Ours has stayed the same since 2006.
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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05-29-2018, 06:01 AM
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#13
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Retired.
Currently Looking...
.
, At Large
Join Date: Jun 2003
Posts: 21,276
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Quote:
Originally Posted by ROBERT CROSS
How does the GAWR change?
Bob
🇱🇷
Ours has stayed the same since 2006.
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I'm with you on this, Bob. I've never seen those numbers change themselves on any vehicle we've had.
As for the OP tweaking and adjusting, I think if it ain't broke, don't fix it. I can't count how many times somebody wanted to get something just a little better, and ended up creating more problems than he solved. And I include me in that group...
__________________
Meddle not in the affairs of dragons, for you are crunchy, and taste good with ketchup.
Terry
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05-29-2018, 08:38 AM
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#14
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Quote:
Originally Posted by overlander63
I'm with you on this, Bob. I've never seen those numbers change themselves on any vehicle we've had.
As for the OP tweaking and adjusting, I think if it ain't broke, don't fix it. I can't count how many times somebody wanted to get something just a little better, and ended up creating more problems than he solved. And I include me in that group...
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Or as the say on the ASF's...."if it ain't broke, fix it 'til it is"
Bob
🇱🇷
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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05-29-2018, 09:13 AM
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#15
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Quote:
Originally Posted by DKB_SATX
You are likely transferring WAY more than 40 lb of tongue weight with your WD hitch.
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Yeah, absolutely agree. I meant 40 lbs over and above transferring the weight back onto the front axle.
Interested if anyone has an explanation for the Airstream owners manual recommendation of putting 1/3 of the tongue weight on the front axle? Maybe more useful for passenger cars that don't expect a disproportionate load to be added to the rear axle like a pickup?
Yes, if it ain't broke don't fix it, except I do think the heavier round bars make a significant improvement. Less "porpoising" with the same amount of weight transferred feels much more stable.
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05-29-2018, 09:16 AM
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#16
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Quote:
Originally Posted by ROBERT CROSS
How does the GAWR change?
Bob
Ours has stayed the same since 2006.
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If that comment was for me I'm sure I confused an acronym somewhere in my original post. Just switch a GVWR for a GVCM, actual vehicle weight or whatever makes sense!
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05-29-2018, 11:30 AM
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#17
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Gvcm 😳
Now I'm really confused🙃
Bob
🇱🇷
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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05-30-2018, 06:19 AM
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#18
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Vintage Kin
Fort Worth
, Texas
Join Date: Nov 2006
Posts: 8,014
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Quote:
Originally Posted by smithcreek
Yeah, absolutely agree. I meant 40 lbs over and above transferring the weight back onto the front axle.
Interested if anyone has an explanation for the Airstream owners manual recommendation of putting 1/3 of the tongue weight on the front axle? Maybe more useful for passenger cars that don't expect a disproportionate load to be added to the rear axle like a pickup?
Yes, if it ain't broke don't fix it, except I do think the heavier round bars make a significant improvement. Less "porpoising" with the same amount of weight transferred feels much more stable.
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It’s part of the old (1960s) rule of thumb that a WDH would (and could) show roughly 33% at Steer, Drive & TT. There was always a variance, so ideally one loaded the Drive Axle 10% heavier than the other two.
Same is true today on big trucks. The tankers I pull require a taller fifth wheel plate than that used with vans (47” approximately). 52-54” is more like it (look for risers). From empty to loaded the Drives wind up with 1800-lbs more product than the tandems. Exceeds State limits earlier (before loading to vehicle gross).
Ideally one winds up with several hundred more on the Drives than the Trailer Tandems (each limited to 34,000-lbs) so as to maintain better traction. (This is with bulk commodity where maximum weight carried is crucial). But an “even” loading is easier to deal with.
The Steer Axle will go from about 9000 when empty to a legal maximum of twelve. One moves the fifth wheel plate to finesse compliance.
A van trailer may carry next to no weight aboard. Or be at maximum. Usually well below. The trailer tandem axles can be shifted a very long ways to accommodate a wide range. Far forward shifts more weight to Drives. Etc.
Where — in big trucks or TT TVs — too much weight remains on the Drive Axle, the ride is tougher than necessary, steering is made weird, and braking/handling aren’t as good as they should be. Can be. The driver wears down faster. So does the equipment.
The “One Third Rule” was similar. Use all three points to minimize or cushion shock force. The trailer tongue is a lever extending back to the center point between axles. TW is static measurement. A placeholder. Force can climb into thousands of pounds in roadgoing dynamics from a hypothetical, original “800-lbs” when the lever is moving over a wide range. WDH dampens that effect. Initially, and finally.
Those who insist only a pickup can do it miss the centrality of WD. Use a vehicle with terrible FF/RR weight bias to start, and compound the road performance problem with terrible roll center height etc. Where the bed load (those thing UNABLE to be carried in passenger compartment or TT) is heavy enough to better “equalize” the FF/RR bias, then we just have a badly-designed (permanently-compromised) car to with which to tow. Higher operational expense, and every mile a higher safety risk (as the bed is likely near empty when solo). Took the long way around to arrive at the same beginning, but now with the worst performance in every situation.
One Third is a descriptive goal.
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05-30-2018, 06:51 AM
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#19
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Rivet Master
2013 20' Flying Cloud
Westerly
, Rhode Island
Join Date: Apr 2018
Posts: 654
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Quote:
Originally Posted by slowmover
Those who insist only a pickup can do it miss the centrality of WD. Use a vehicle with terrible FF/RR weight bias to start, and compound the road performance problem with terrible roll center height etc. Where the bed load (those thing UNABLE to be carried in passenger compartment or TT) is heavy enough to better “equalize” the FF/RR bias, then we just have a badly-designed (permanently-compromised) car to with which to tow. Higher operational expense, and every mile a higher safety risk (as the bed is likely near empty when solo). Took the long way around to arrive at the same beginning, but now with the worst performance in every situation.
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That all makes sense. Pickups were designed to carry a static load in the bed and drive well while doing it. With no load the tail end is barely heavy enough to keep traction on a dewy morning!
On my drive to the scales I had the WD chains hitched one ring higher than I usually did, trying to get more weight on the front axle like Airstream called for. I could feel the back end was lighter and it was the only time the wheels did spin for an instant pulling away at a stop light.
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05-30-2018, 02:37 PM
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#20
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Rivet Master
1972 31' Sovereign
1975 31' Excella 500
Currently Looking...
Benton
, Arkansas
Join Date: Mar 2013
Posts: 5,868
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Here is my take, I adjust the WD bars until my truck sits kinda level and it drives great. If I have my tool box in the truck bed I tighten them more, if I don’t I tighten them less. After I start out, if the rear axle feels heavy or light, I pull over and make an adjustment. It works for me, it’s free, and it’s no hassle. The goal for me is comfort and stability.
On that note, I have weighed and adjusted everything “according to Hoyle”, but in the end adjusting by the seat of my pants delivers the best results. That’s me though, your results may vary.
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The fact that I am opinionated does not presuppose that I am wrong......
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