CAT Scale weights are confusing me.

[Atlee]

Weighted my truck and trailer Friday, before we went on a weekend camping trip. The trailer is brand new. It had never been out camping before.

My WDH is the Blue OX Sway Pro. With 1k bars. I put it up to the 9th Chain link as called for in the book, and the Tech who installed the the Blue Ox
First, my TV is a 2014 F150 XLT 4x4, Supercab, 8 ft box, with Max Tow Package, and the HDPP. The FGAWR = 4050#, RGAWR = 4800#, GVWR = 8200#, CCC = 2286#, and the GCWR = 17,100#. The truck was rigged for towing, meaning all the normal tools, generators, gasoline, compressor, etc were on board as well as a full tank of gasoline.

My travel trailer is a new Jayco Jay Flight 23RB. It's a "stick and tin" built trailer and no slide. GAWR = 3500# each, GVWR = 6500#, Factory Shipped weight = 4758#, CCC = 1742#.

These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

[jadatis]

Then your trailer is exeption to the rule.
Exeptions make the rule.

[atwowheelguy]

jadatis wrote:
GVWR is in rule always less then the GAWR's added up, and this is to allow some weightshifting between the axles.

This is not the case for the GVWR of my trailer. My camper has two 3500 lb. rated axles. The quoted dry tongue weight is 765. The GVWR is 7765, the sum of the axle ratings and the dry tongue weight.

[jadatis]

Reaction to above.

Also added up the WDH engaged 3 weights and so total weight must be typing error.
But this explanes the large difference of 100 lbs it gave between WDH engaged and disengaged, now its only 40 lbs difference, because of measuring differences of scale, and not 100.

GVWR is in rule always less then the GAWR's added up, and this is to allow some weightshifting between the axles.

For TV this means that you can still put some more load to front or back without overloading one of the axles, but in practice if loaded to GVWR, mostly rear axle is at its GAWR or even a bit overloaded, and front is way below GAWR, by the way you can load a car( space for load only at rear even behind rear axle, and towbar)

For tandem-axle Trailer, like you have, the hight of the towbar influences the weightdivision between the axles.
If your towbar is higher placed then average, it lifts up the front axle of trailer, so larger part of total weight on rear axle and front axle less, and the other way around.
Then if realy loaded Trailer to 6500 lbs, the weights on axles can be , 3500 lbs on rear axle and only 3000 on front axle.
Lower towbar is the other way around.

This differce in towbar hight happens when WDH engaged and disengaged, so if you would also have weighed the Trailer axles seperately, you would have notice next.
WDH disengaged> towbar lower> Loaddivision F+/R-.
WDH engaged > towbar higher> loaddivision F-/R+.

For axles only counts the total axle weight max allowed so GAWR,
but for pressure advice-advice you have to be ware.
Then even for that the crossed weightdivision between axles, is not important , only highest axle-end counts for setting the pressure, because rule is to give both sides on the axle the same presssure.

[atwowheelguy]

Atlee wrote:
Weighted my truck and trailer Friday, before we went on a weekend camping trip. The trailer is brand new. It had never been out camping before.

My WDH is the Blue OX Sway Pro. With 1k bars. I put it up to the 9th Chain link as called for in the book, and the Tech who installed the the Blue Ox
First, my TV is a 2014 F150 XLT 4x4, Supercab, 8 ft box, with Max Tow Package, and the HDPP. The FGAWR = 4050#, RGAWR = 4800#, GVWR = 8200#, CCC = 2286#, and the GCWR = 17,100#. The truck was rigged for towing, meaning all the normal tools, generators, gasoline, compressor, etc were on board as well as a full tank of gasoline.

My travel trailer is a new Jayco Jay Flight 23RB. It's a "stick and tin" built trailer and no slide. GAWR = 3500# each, GVWR = 6500#, Factory Shipped weight = 4758#, CCC = 1742#.

These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

Unless I made a typo, the total with WDH engaged is 13,260, not 13,200.

Seems odd that the trailer GVWR is less than the two axles.

Did you weigh the truck only without the hitch head installed? That would determine if the hitch head weight is included in the tongue weight.

I made a guess that your hitch receiver is rated for 1100 since you didn't list it. Looks like your truck has more load carrying capacity remaining than the trailer. That's the opposite of most.

[JBarca]

Atlee wrote:
Thanks for asking. I just checked the scale tickets again. They are correct as listed. One of those weird circumstances.

JBarca wrote:

Atlee wrote:


These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

Hi Atlee,

Just asking in case you had a typo and we are figuring math off your numbers. Check your weight slips. While not impossible... more unusual that your steer axle lost weight to come out exactly (3,340#) which is the same as the rear axle (3,340#) before hitching up. It might be, just checking a typo did not happen.

Thanks

John

OK Got it. Thanks for checking. Yup, weird, but it happens....

[Atlee]

Thanks for asking. I just checked the scale tickets again. They are correct as listed. One of those weird circumstances.

JBarca wrote:

Atlee wrote:


These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

Hi Atlee,

Just asking in case you had a typo and we are figuring math off your numbers. Check your weight slips. While not impossible... more unusual that your steer axle lost weight to come out exactly (3,340#) which is the same as the rear axle (3,340#) before hitching up. It might be, just checking a typo did not happen.

Thanks

John

[JBarca]

Atlee wrote:


These are my numbers from my weigh tickets. Truck with no trailer, Steer Axle 3660#, Drive Axle = 3340#, Gross Weight = 7000#

Truck with trailer, but WDH disengaged. SA = 3340#, DA = 4640#, Trailer Axle = 5320#, Combined Gross Weight = 13,300#

Truck with trailer, but with WDH engaged. SA = 3520#, DA = 4280#, TA = 5460, GCWR = 13,200.

Hi Atlee,

Just asking in case you had a typo and we are figuring math off your numbers. Check your weight slips. While not impossible... more unusual that your steer axle lost weight to come out exactly (3,340#) which is the same as the rear axle (3,340#) before hitching up. It might be, just checking a typo did not happen.

Thanks

John

[JBarca]

BarneyS wrote:
jadatis wrote:

Maximum allowed tonge-weight in America is as far a I know 15% so this 15.5% would not give problems when weighed by police , I think.
Snip...

America has no "maximum allowed" tongue weight.- at least non that I have ever heard of. In fact, there are NO recreational vehicle regulations or laws pertaining to tongue weight at all or even axle weights as far as I know.

Barney is dead on.

It is common for a trailer like a TT, (some times referred to as "conventional towing") that this trailer type has a "recommended" loaded tongue weight of between 10 to 15% for good towing dynamics in relation to trailer sway. The 15% higher end is that, a recommendation as when this goes higher, many (not all) tow vehicles can have issues holding up higher then 15% tongue weight. And pending the vehicle, some cannot handle the full 15% while other vehicles can handle 20 % plus load tongue weight. My prior TT had a floor plan where the "dry" trailer tongue weight started at 15.5% dry tongue weight and went up into the 20% + after I started loading it. For sure it towed stable but also made me trade my 1500 truck in on a K2500 Suburban.

Think of a gooseneck horse trailer, the wheels are way in the back and the tow ball is all the way in the front. These have large TW's by design and the truck needs to have the payload to carry it.

Hope this helps

John

[BarneyS]

jadatis wrote:

Maximum allowed tonge-weight in America is as far a I know 15% so this 15.5% would not give problems when weighed by police , I think.
Snip...

America has no "maximum allowed" tongue weight.- at least non that I have ever heard of. In fact, there are NO recreational vehicle regulations or laws pertaining to tongue weight at all or even axle weights as far as I know. Any axle weight regulations that pertain to commercial vehicles would apply to any RV trailer also but are so high that no RV currently made could exceed them and are therefore irrelevant.

The only "laws" that could apply here are physics. If you do not have enough tongue weight the stability of the trailer is compromised. The general rule of thumb in America is around 15% but it is not a "law".
See this video for a good demonstration (got video from another post).
Barney

[Atlee]

It was loaded except for my wife who was inside the office. But the numbers I quoted were the numbers off the CAT scale tickets plus her weight of 120#. At first I was splitting the weight 50-50 but a more realistic estimate is probably 60 front and 40 rear. The front seat is a lot closer to the front axle than the rear axle.

jadatis wrote:
Maximum allowed tonge-weight in America is as far a I know 15% so this 15.5% would not give problems when weighed by police , I think.
And indeed this is when you would weigh the tonge off the TV with a device.
So this is the weight when WDH is disabled.

See what a treasure of information this weighing gives, so I agree with RCMAN46.
And you also did it the right way.
But it can be better , by weighing per axle-end in all the different situations.
Would though also give more measuring differences by the inacuracy of the scale.
And did you weigh with all the persons in the car?, Otherwise you could yust estimate that one person , what effect it has on weights on front and rear, by the place he/she sits. Again some inacuracy it gives.
But for instance to determine the needed tirepressure, it is acurate enaugh, because you then always have to add a percentage to the weighed loads for R/L unbalance, and pressure-loss in time, etc.
As "pigheaded Dutch Selfdeclared tirepressure-speialist" I then can help you , but need also tire-specifications.

[jadatis]

Maximum allowed tonge-weight in America is as far a I know 15% so this 15.5% would not give problems when weighed by police , I think.
And indeed this is when you would weigh the tonge off the TV with a device.
So this is the weight when WDH is disabled.

See what a treasure of information this weighing gives, so I agree with RCMAN46.
And you also did it the right way.
But it can be better , by weighing per axle-end in all the different situations.
Would though also give more measuring differences by the inacuracy of the scale.
And did you weigh with all the persons in the car?, Otherwise you could yust estimate that one person , what effect it has on weights on front and rear, by the place he/she sits. Again some inacuracy it gives.
But for instance to determine the needed tirepressure, it is acurate enaugh, because you then always have to add a percentage to the weighed loads for R/L unbalance, and pressure-loss in time, etc.
As "pigheaded Dutch Selfdeclared tirepressure-speialist" I then can help you , but need also tire-specifications.

[mike-s]

Atlee wrote:
I thought if I weighed the truck and trailer with and without the spring bars engaged, I could get a close approximation of the tongue weight.

What combination of those numbers would give that to me?

For that, ignore the WDH measurements, because that shifts effective weight off the tongue. The real tongue weight is:

Trailer weighs 13300-7000 = 6300 lbs (from gross weights).
Tongue weight is 6300-5320 = 980 lbs (trailer weight - trailer axle)

[RCMAN46]

Congratulations.

I have seen many posts with Cat scale numbers.

You have done the process the way it is supposed to be done.

That is three weights and it appears the correct axles were on the correct scale pads each time.

From your numbers I get a trailer weight of 6300 lbs and a tongue weight of 980 lbs which gives a tongue weight percentage of 15.5%

Assuming the trailer is level or slightly front low you should have a trailer that tows well.

As for accuracy of scale numbers CAT scales or +/- 40 lbs and if there was any significant wind during the scaling that can account for the 100 lb difference.

[Atlee]

Thanks for the explanation.

jadatis wrote:
The 100 lbs difference between WDH and no WDH is mesuring difference of the scale, but this is not what you think is strange.

WDH transports a part of Hichweight from rear tires of TV to front tires of TV and Trailer tires, and that is yust what you noticed when weighing.

The difference rear axle between only TV and trailer with WDH disengaged, is 4640lbs-3340 lbs= 1300 lbs, and you think then that this is the tonge-weight.
But this is by leaverworking not the tonge-weight.
Example : asume hich of TV placed half of the wheelbase ( distance front axle to rear axle)behind the rear axle, then real hich weight would be 1/1.5=2/3th of that is 865 lbs . But you can measure it yourselfes acurate enaugh to estimate your real tonge-weight.

The front axle is lifted up a bit by that same leaver working.
It gives for same compare
, 3660lbs-3340 lbs= 330 lbs less.

You can also substract the front from rear is 1300 lbs - 330 lbs= 970 lbs.
And this is your tonge weight exactly , only difference can be measuring differences of scale.

From this we can also calculate howmuch your hich of TV is placed behind the rear axle in ratio of wheelbase and that is 1300/970= 1.34 so hich 34% of wheelbase behind the rear axle.
Chech it yourselfes by measuring wheelbase and distance rear axle to hich of TV. Most acurate is measuring from front-side of front wheel to front side of rear wheel, middle of a wheel is not always so easy to determine.
From rear axle to hich is not as axurate to measure, but its yust for the idea.

Then if wheelbase is for instance 10 feet( foot??) , the distance rear axle to hitch is 34% of that is 3.4 feet aproximately.

EDIT: its even more easy to determine tongue-weight, by comparing the gross weights.
That is TV without trailer atached 7000 lbs.
TV with Trailer atached WDH not set 7980 lbs.
TV with Trailer atached WDH set 7900 lbs.
Tonge weight is then difference between no trailer atached and with trailer atached, and is between 900 and 980 lbs.
The difference is measuring differences, a calcibrated scale is allowed to give 1 measuring step different wich is mostly 20 lbs, and then even it can be in between the next steps, so measuring difference can rise to a small 40 lbs.
This per axle weighed can rise to 60 to 120 lbs difference in measurement. We asume your real total weights did not chanche during the measurement proces.

Another EDIT: the difference of trailer atached and not atached of 80 lbs is in theory the part that goes to the trailer tires by engaging the hich. Part of tonge weight goes not only to front tires but also to trailer tires. Read 5460-5320=140 lbs and only TV gross weights (determined by front+rear axles weight added) suggest 80 lbs, diffence is because of measuring differences of scale.

[jadatis]

The 100 lbs difference between WDH and no WDH is mesuring difference of the scale, but this is not what you think is strange.

WDH transports a part of Hichweight from rear tires of TV to front tires of TV and Trailer tires, and that is yust what you noticed when weighing.

The difference rear axle between only TV and trailer with WDH disengaged, is 4640lbs-3340 lbs= 1300 lbs, and you think then that this is the tonge-weight.
But this is by leaverworking not the tonge-weight.
Example : asume hich of TV placed half of the wheelbase ( distance front axle to rear axle)behind the rear axle, then real hich weight would be 1/1.5=2/3th of that is 865 lbs . But you can measure it yourselfes acurate enaugh to estimate your real tonge-weight.

The front axle is lifted up a bit by that same leaver working.
It gives for same compare
, 3660lbs-3340 lbs= 330 lbs less.

You can also substract the front from rear is 1300 lbs - 330 lbs= 970 lbs.
And this is your tonge weight exactly , only difference can be measuring differences of scale.

From this we can also calculate howmuch your hich of TV is placed behind the rear axle in ratio of wheelbase and that is 1300/970= 1.34 so hich 34% of wheelbase behind the rear axle.
Chech it yourselfes by measuring wheelbase and distance rear axle to hich of TV. Most acurate is measuring from front-side of front wheel to front side of rear wheel, middle of a wheel is not always so easy to determine.
From rear axle to hich is not as axurate to measure, but its yust for the idea.

Then if wheelbase is for instance 10 feet( foot??) , the distance rear axle to hitch is 34% of that is 3.4 feet aproximately.

EDIT: its even more easy to determine tongue-weight, by comparing the gross weights.
That is TV without trailer atached 7000 lbs.
TV with Trailer atached WDH not set 7980 lbs.
TV with Trailer atached WDH set 7900 lbs.
Tonge weight is then difference between no trailer atached and with trailer atached, and is between 900 and 980 lbs.
The difference is measuring differences, a calcibrated scale is allowed to give 1 measuring step different wich is mostly 20 lbs, and then even it can be in between the next steps, so measuring difference can rise to a small 40 lbs.
This per axle weighed can rise to 60 to 120 lbs difference in measurement. We asume your real total weights did not chanche during the measurement proces.

Another EDIT: the difference of trailer atached and not atached of 80 lbs is in theory the part that goes to the trailer tires by engaging the hich. Part of tonge weight goes not only to front tires but also to trailer tires. Read 5460-5320=140 lbs and only TV gross weights (determined by front+rear axles weight added) suggest 80 lbs, diffence is because of measuring differences of scale.