Help me understand my Cat scale numbers

[Ericl]

I weighed my truck and trailer yesterday

2017 Chevy Siverado info
GVWR -7,400 lbs
Curb weight - 5,035 lbs
max payload -1669 lbs
GCWR - 15,000 lbs
GAWR FRT - 3,850
GAWR RR - 3,950

truck data from scales
Steer axle : 3240 lbs
Drive axle : 2620 lbs
Gross Wt. : 5860 lbs

Truck and trailer
Steer axle : 3140 lbs
Drive axle : 3840 lbs
Trailer axle : 6580 lbs
Gross Wt. : 13,560 lbs

Trailer is 2021 white hawk 28rl
Hitch is propride 1400#

Steer axle dropped 100 lbs
Drive axle gained 1,220 lbs (COVID-19)
1,440 lbs below GCWR
110 lbs below rear GAWR
710 lbs below front GAWR

if I apply more tension the the WDH will the lighten the back end and but more weight on the front axle? Trailer was basically loaded for travel but not the truck. Does this mean I have 110 lbs remaining for cargo in the bed?

Thank you in advance. I read many different post and I get get my head around it.

Eric

[MichaelO]

I’m following so I can learn too.

[colby]

You are missing one weigh. Follow the instructions here - https://www.jaycoowners.com/forums/f...v-tt-3871.html and this site has a nice worksheet that helps - https://fifthwheelst.com/rv-weighing-worksheet.html

Essentially it is three weighs - TV and RV with WDH engaged, TV and Trailer with WDH not engaged and TV by itself (with hitch and bars still connected or stowed in the bed, somewhere where the weight counts)

[NewBlackDak]

You need to get more back onto the steer axle. On most hitches it’s done by tilting the head down a bit more. Keep in mind that every person/pet/blanket/pillow/bag/personal device will add weight. If you didn’t weight with all your people and stuff in the cab, it’s not a good weigh.

[Ericl]

Thank you Colby will do as instructions,
New Black Dak,
Does increasing the tension on the hitch force more weight to the front axle? In lieu of loading up I was leaving my truck empty, except fuel, at that point knowing what I have left.

[Rustic Eagle]

Ericl,

Originally Posted by Ericl

snip...... if I apply more tension the the WDH will the lighten the back end and but more weight on the front axle?.....snip

The ProPride WDH set-up & adjustment procedures are different than that of a conventional WDH, refer to your specific ProPride adjustment documentation. Increasing spring bar tension will distribute additional weight 'off' the TV's rear axle to the TV's front axle....., you may also see a little weight distributed back to the TT axles as well.

Originally Posted by Ericl

snip......Trailer was basically loaded for travel but not the truck. Does this mean I have 110 lbs remaining for cargo in the bed?.......snip

Basically yes........, adding another 110lbs of cargo 'over' the TV's rear axle you will reach your TV's specified 3,950lb rear GAWR. This is based on your posted TV/TT loaded conditions at the CAT.

Also, based on your CAT scale results you have 420lbs of 'available' TV cargo capacity remaining based on the TV's GVWR of 7,400lbs...., but it appears your rear axle weight limit will be reached first and not allow you to use all of the 420lbs available based on your present TV/TT loaded conditions.

As mentioned, there is a 3rd weigh process (w/WDH spring bars dis-engaged) required to complete the TT weigh-in process (loaded tongue weight, etc.). This data will allow you to confirm if your loaded tongue weight falls within the recommend 13% to 15% of the TT's gross weight.

Double check my math......

Bob

[Ericl]

Rustic Eagle,

Thank you, I guess I was overthinking it. I installed the pro-pride myself and I have the stinger set up pretty much horizontal, is the goal for the front axle to get the weight as close to where it is less trailer? If I increase the tension to force the 100 lbs to the front, does it remove 100 lbs off the back? Sean’s instructions for the hitch are good, but only include measurements to the wheel wells.

[Rustic Eagle]

Ericl,

Originally Posted by Ericl

snip...... is the goal for the front axle to get the weight as close to where it is less trailer?....snip

Yes, that's the goal in restoring the TV's front suspension, steering, and braking characteristics. Since all TV suspensions react differently to a WDH weight return adjustment the "how close" to the "TV only" front axle weight can very.

I try and get my front axle weight return as close as possible so that any minor added weight to my tongue weight doesn't notably affect TV handling characteristics.

Originally Posted by Ericl

snip......If I increase the tension to force the 100 lbs to the front, does it remove 100 lbs off the back?.......snip

In theory yes..., but at the CAT scale it may not represent an exact pound-for- pound transfer because of the physics in play with WDH leveraging forces taking place through the TV and TT frames.

Your TV/TT hitched CAT results has you 100lbs shy of your TV only front axle weight which is actually pretty good all things considered. If you were north of 100lbs then a WDH re-adjustment would be warranted.

Originally Posted by Ericl

snip......Sean’s instructions for the hitch are good, but only include measurements to the wheel wells.

The wheel well measurement procedure has been widely used for decades by most WDH manufactures and will get you in the "ballpark". Some TV Owners Manuals will reference a "percent" return front fender height range when using a WDH..., but don't reference what this means in terms of "weight".

The CAT scale is the only way to dial-in a WDH adjustment resulting in an actual front axle "weight" return value.

Bob

[Ericl]

Thank you Bob, crystal clear now

[E_Benson]

I have a ProPride and there is a quicker way that works well. Just measure your ground to front fender gap before you put the trailer on. Hitch up and keep cranking your weight distribution bars until you get back to within ~1/2" or so of your original measurement. There is not worry of sway in the pro-pride so this will get you where you need for best handling characteristics. Plus, you as you change your trailer weight, water in the tanks etc, you can always get back to a good distribution due to infinite adjustment of the distribution bars.

If you can't get as much transfer to the front just adjust the angle of the stinger. On the stinger just put 1-2 more washers to slightly point the stinger down as it will get more leverage when the bars are cranked. It makes it a little tricker to insert the stinger you have a more extreme angle, but if you are already horizontal a washer or 2 will only help and not impact your hookup.


Eric

[Ericl]

Originally Posted by E_Benson

I have a ProPride and there is a quicker way that works well. Just measure your ground to front fender gap before you put the trailer on. Hitch up and keep cranking your weight distribution bars until you get back to within ~1/2" or so of your original measurement. There is not worry of sway in the pro-pride so this will get you where you need for best handling characteristics. Plus, you as you change your trailer weight, water in the tanks etc, you can always get back to a good distribution due to infinite adjustment of the distribution bars.

If you can't get as much transfer to the front just adjust the angle of the stinger. On the stinger just put 1-2 more washers to slightly point the stinger down as it will get more leverage when the bars are cranked. It makes it a little tricker to insert the stinger you have a more extreme angle, but if you are already horizontal a washer or 2 will only help and not impact your hookup.


Eric

Stinger has 2 washers, level to the ground, and the front wheel wells are about 1/2” from unhitched measurement. I’m only up 4.5” on the tower jacks so I have room to add the extra 100 lbs. the test drive that I did the trailer tracked really nice, sharp lane changes and passing 18 wheelers on the interstate.

[Rustic Eagle]

Originally Posted by Ericl

snip.......≥ the test drive that I did the trailer tracked really nice, sharp lane changes and passing 18 wheelers on the interstate.

Bob

[jeepjeepster]

Originally Posted by Ericl

Rustic Eagle,

Thank you, I guess I was overthinking it. I installed the pro-pride myself and I have the stinger set up pretty much horizontal, is the goal for the front axle to get the weight as close to where it is less trailer? If I increase the tension to force the 100 lbs to the front, does it remove 100 lbs off the back? Sean’s instructions for the hitch are good, but only include measurements to the wheel wells.

I could be wrong here, but I believe if you remove 100lbs from the rear axle, it will put ~50lbs on the trailer and ~50lbs on the front axle of the truck. This all depends on the spacing of the axles which is why I used the ~. If you wanted to put 100lbs of additional weight on the front axle it would remove ~200lbs from the rear axle.

[Rustic Eagle]

Jeepjeepster,

Welcome to JOF

Originally Posted by jeepjeepster

snip......I believe if you remove 100lbs from the rear axle, it will put ~50lbs on the trailer and ~50lbs on the front axle of the truck. This all depends on the spacing of the axles which is why I used the ~........snip

You're correct that axle locations can influence weight distribution (amount of) via the WDH. There are a lot of variables that come into play when using a WDH.

The design of the WDH and the direct leveraging forces being applied against the TV's entire suspension will result in distributing a notably higher percentage of weight off the TV rear axle back to the TV's front axle..., a lesser percentage to the trailer axle(s).

Bob

[Ericl]

Thank you Jeepster,thank you Bob,

Sounds like if a put a little more weight on the steering axle, I could load a styrofoam Ice chest and six pack of beer in the bed of the truck

[JonathanCP]

For a true weigh you need to have the truck and trailer loaded as for travel, my fresh water tank is to the rear of the axel, it carries 385lb of water, I use this to counter balance the tongue weight if its too high or low by adjusting how much water I carry, ( as long as I stay in the GVWR of the trailer).

[jadatis]

Originally Posted by Ericl

I weighed my truck and trailer yesterday

2017 Chevy Siverado info
GVWR -7,400 lbs
Curb weight - 5,035 lbs
max payload -1669 lbs
GCWR - 15,000 lbs
GAWR FRT - 3,850
GAWR RR - 3,950

truck data from scales
Steer axle : 3240 lbs
Drive axle : 2620 lbs
Gross Wt. : 5860 lbs

Truck and trailer
Steer axle : 3140 lbs
Drive axle : 3840 lbs
Trailer axle : 6580 lbs
Gross Wt. : 13,560 lbs

Trailer is 2021 white hawk 28rl
Hitch is propride 1400#

Steer axle dropped 100 lbs
Drive axle gained 1,220 lbs (COVID-19)
1,440 lbs below GCWR
110 lbs below rear GAWR
710 lbs below front GAWR

if I apply more tension the the WDH will the lighten the back end and but more weight on the front axle? Trailer was basically loaded for travel but not the truck. Does this mean I have 110 lbs remaining for cargo in the bed?

Thank you in advance. I read many different post and I get get my head around it.

Eric

I suspect a tandem-axle trailer, because of the low weightreduction of front axle.
If you tighten the WDH weight on rearaxle of car gets less, and most weight is shifted to the ( both) trailer axle, and yust a little to frontaxle.

So am I right about the tandem axle trailer?
And what are the reserves for the axles, so GAWR of eachbtandemaxle.

[Ericl]

Originally Posted by jadatis

I suspect a tandem-axle trailer, because of the low weightreduction of front axle.
If you tighten the WDH weight on rearaxle of car gets less, and most weight is shifted to the ( both) trailer axle, and yust a little to frontaxle.

So am I right about the tandem axle trailer?
And what are the reserves for the axles, so GAWR of eachbtandemaxle.

Jadatis, yes it is tandem axle, based on my just completed weights the wdh added 180 lbs to the trailer axle, removed 560 lbs from the tv drive axle, and added 440 lbs to tv steer axle.

My next post will layout my numbers

[Ericl]

Thank you everyone for your help on this. I finally got back to the scales on the way out for a 2 week trip. I used the Sticky from Denise and Bob.

If I did this correctly all numbers are in line as per the sticky, barely. The one I am high on is GM’s published GAWR RR (3,950) actual 4,080 so I’m 130 lbs over. I can shave that. I recommend everyone go through this, I had know clue prior to. Not to say the CAT Czars are going to chew up and spit out my math.

Here they are

Loaded TT weight: (2nd weigh TV/TT gross weight) minus (1st weigh TV gross weight). Loaded tt weight. 14,360 - 6,320 = 8,040

Loaded Tongue weight: (3rd weigh TV axle weights) minus (1st weigh TV gross weight). Tongue weight should be 10% -15% of loaded TT weight (13%-15% on longer TT’s). loaded tongue weight 2,840 + 4,640 = 7,480 - 6,320 = 1,160 (14.4%)

Loaded TV weight: 1st weigh gross weight. 6,320

Loaded TV/TT weight: 2nd weigh gross weight. 14,360

TT GVWR: Confirm that the “Loaded TT weight” doesn't exceed the TT GVWR. 8,150 TT GVWR - 8,040 CAT = 110

TV GVWR: (2nd weigh steering axle weight) plus (2nd weigh drive axle weight) sum total should be less than the TV GVWR. 3,280 + 4,080 = 7,360 (7,400)

TV Axle limits: The 2nd weigh TV axle weights shouldn’t exceed the GAWR (F/R) limits noted on your TV’s driver’s door. 7,360 (7,800)

TV GCWR: The 2nd weigh gross weight should be less than specified TV GCWR. 14,360 (15,000)

[Rustic Eagle]

Originally Posted by Ericl

snip...... I recommend everyone go through this,.....snip

X2

Your summery looks great and provides a factual weight snap-shot of your TV/TT combination based on your personal loading habits.

It's good to know when a TV/TT combination is pushing critical weight limits under one's normal ready-to-camp conditions.

Bob