How to weigh your rv

[Raz]

Originally Posted by Glenn Baglo

I wasn't worried about Larry.
I was trying to understand my own situation. I have weights for RAV front axle, rear axle and the trailer axle, but WDH was employed at the time. So, I was wondering if there is a calculation that would take that into account.

Since your hitch will shift weight from the hitch point both forward and back, the weight at each axle seems what you would want. To get that you weigh just the front axle with trailer off the scale. Then just the trailer axle with the TV connected but off scale. Finally the whole thing. Subtract the first two and you're there. Raz

[Carol H]

Originally Posted by Glenn Baglo

I wasn't worried about Larry.
I was trying to understand my own situation. .

sorry Glenn I though you were just poking fun at my total lack of ability in regards to being clairvoyant.

[Paul O.]

Look at it this way. Case 1: Without the WD hitch the tongue weight is going to load the rear axle of the TV more, the front axle of the TV less, and the TT axle no change.

Case 2: With the WD hitch the forces of the hitch spring bars are going to load the TV rear axle less, the TV front axle more, and also the TT axle more.

The WD hitch puts high bending forces on the TV frame as well as on the TT frame in order to achieve this. The WD hitch creates a rigid beam connection where without it the ball allows free movement. Driving on a flat road is all good, but as soon as you have to pull into a sloped driveway, across a drainage ditch, or even some of the "dips" I remember from the Tucson area roads or the streets of Denver, I bet you stress those frames quite a lot. (A case for 5th wheel.) I would not use the WD hitch unless I was forced to.

It sounds like Glenn has three numbers from the scales. He needs two more: front axle of the TV and the rear axle of the TV without the trailer. Then it becomes clear what his WD hitch is doing.

[Borden]

Propane x 2 38lbs each, battery 61lbs remove them and Carole can lift the tongue on our boler on flat ground and move it by her self. Should be safe on scale for that part. Bit afraid to check new full weight as I am shure have added weight with the rebuilding of our trailer.

PS. boler towing directions recommend WD system for towing and our car seems to work fine with it.

[Joe Romas]

I use my Sherline tongue weight scale to weigh my loaded trailer before leaving home.
If you pay $20 5 times your at what I paid for my scale
Mine was on sale but here's what I have.
https://www.propridehitch.com/sherli...-weight-scale/

For a total weight I crank down my rear jacks and front jack until the wheels are off the ground.
Put the scale on my floor jack and lift at the three points measuring each of the three points, add them up and there you go for a total.
For side to side weight I place the scale with the rear jacks up and measure each side lifting the wheel off the ground with the floor jack under the frame by the axle.


Three years in a row my 17' 1999 Casita SD loaded weighted just under 3000# TOTAL.

My axle is rated at 3500#

Joe

[DeadEyeDan]

We were just in Oregon. Apparently they leave their truck scales on when the scales are closed so anyone can pull in and weigh their rig.

We weighed each truck axle separately, but weighed the trailer axles together.

Since the trailer was attached, this did not account for the tongue weight so when I got home, I took the truck to the local truck stop and got a fully loaded weight minus the trailer.

If I did the math right, the tongue weight should be the hitched truck weight minus the unhitched truck weight.

[gordon2]

Originally Posted by Joe Romas

....
For a total weight I crank down my rear jacks and front jack until the wheels are off the ground....

Joe

Sorry to be late to the party but I just saw this post from November.. and my mouth went

rear jacks meaning stabilizer? .....

[Iowa Dave]

Places you can make friends and then get your rig weighed for no cost. ( in Iowa)
Landfills. Go when not busy
Rock, sand and gravel quarries. Go when not busy
Grain elevators. Call ahead and take some cookies
Some trucking firms have scales especially if they are associated with warehousing.
Figure out if you know anybody who works at one of these places or ask when you’re there buying something.
Is this Heaven? No it is Iowa
Iowa Dave

[Thelless]

The proper way would be to use individual wheel scales and weigh everything loaded like you camp. Weigh the truck separate first, then weigh the truck and trailer. It will require 8 scales. 1 for each wheel. this will give you all the numbers you need.

[John in Santa Cruz]

um, the easy way is to use a truck scale. drive just the truck front axle onto the scale, get a reading A, drive both truck axles onto the scale, get another reading B, then hitch up the trailer, and get truck front axle D, front+rear E, and truck+trailer F

the truck rear axle weight laden is E-D
the truck front axle weight laden is D
the trailer total weight is F - B
the trailer tongue weight is E - B
trailer axle weight is F-E,

F is, of course, the gross combined weight. (GCW).


if D is significantly less than A, odds are you should be using a WDH as your trailer tongue weight is unloading your front suspension.

my local county dump transfer station will let you weigh for free if you're willing to write down the numbers yourself (the large digital readout is visible through the window). if you want a weight slip, they'll charge you a nominal fee for the weighing.

[V'sGlassSleeper]

Joe,

This sounds like a practical way to weigh one's trailer, but I'm not sure I understand the process. Are you saying that you use your stabilizer jacks to support the entire weight of the trailer while you have the scale under the tongue jack? I thought using the stabilizer jacks that way was a no-no?

I can't visualize the weighing process that you are explaining in order to get the final total trailer weight. Would you be so kind as to draw a diagram?

I would prefer to be able to weigh my tongue and trailer at home - the only time I've weighed my trailer on a truck scale, I did not dare unhitch because of the long line of trucks behind me. Living in a big city, I am not sure if there's ever a "slow time" at the scales when I could take the time to unhitch the trailer from the truck.

[John in Santa Cruz]

unhitch out of the way somewhere, take a pass through the scales with just the truck, get the front axle (A1) and both axle weights (B1).

now hitch up, get back in line, and get front axle (A2), both truck axles (B2), and total combined weights (C).

tongue weight is B2-B1

total trailer weight is C-B1

trailer axle weight is C-B2

[Joe Romas]

Originally Posted by V'sGlassSleeper

Joe,

This sounds like a practical way to weigh one's trailer, but I'm not sure I understand the process. Are you saying that you use your stabilizer jacks to support the entire weight of the trailer while you have the scale under the tongue jack? I thought using the stabilizer jacks that way was a no-no?

I can't visualize the weighing process that you are explaining in order to get the final total trailer weight. Would you be so kind as to draw a diagram?

I have taken the designed for pop up camper "stabilizers" off and put on scissors jacks midway between the rear bumper and wheels. This modification is becoming popular on Casitas and as of a month ago new Casita trailers come that way from the factory. Makes for a more stable trailer when parked. And yes at least mine are rated at 2500# each and are capable of lifting the wheels off the ground.
Now picture in your mind the trailer totally supported on the two scissors jacks in the rear and tongue jack on the front, three points.
Then using my $59 Harbor Freight floor jack with my Sherline tongue weight scale on the jack lift one at a time each of the three points until the jack and scale are supporting the weight at that point. Record the weight and do the other two points the same way. Add the three for a total.
We're going on a long weekend rally and I weighted my 17' SD just this morning.
The rear jack points came in at 1100# each and the tongue was 1000# for a total of 3200#.
The Sherline scales claim within 2% accuracy at mid range of the gauge. My gauge goes up to 2000 pounds, right where my weights are, so a 2% variance is plus or minus or from 3136# to 3264#

[V'sGlassSleeper]

Thanks for the responses, John and Joe,

I think I will go with John's very practical suggestion first and - depending on how much my travel trailer's weight tends to vary when I really start using it regularly - then I might try to weigh it at home using Joe's method.

John, just to clarify, I would get the front truck axle weight (A1) all by itself by positioning the front axle on the first scale, with the rear axle on the second scale - and then adding the total of the two readings to get the weight of both axles (B1) - is that correct?


With digital technology and sensors becoming so lightweight and portable, I am kind of surprised that there is no system available that uses lightweight flexible panels (like the ones used for solar panels) as scales hooked up to a central digital device that would allow a user to drive onto the panels and get an accourate weight reading. Maybe one of the forum engineers will develop one and get it to market!

[Glenn Baglo]

I use a truck scale to weigh the trailer and a Sherline to weigh the tongue.
I have a 1,000 lb. gauge which puts my tongue weight of 340 lbs. close to mid-range.
The 2,000 lb. gauge ( which I kept ) is too hard to read and not as accurate at 340 lbs.

[John in Santa Cruz]

Originally Posted by V'sGlassSleeper

John, just to clarify, I would get the front truck axle weight (A1) all by itself by positioning the front axle on the first scale, with the rear axle on the second scale - and then adding the total of the two readings to get the weight of both axles (B1) - is that correct?

a commercial truck scale can weigh the whole vehicle at once. so you drive just the front axle onto it, and they take a reading, then you drive both axles onto it, and take a second reading, they print this out on a paper strip and give it to you. if you want to know your rear axle weight, subtract the first reading from the second combined reading.

[V'sGlassSleeper]

Great, thanks, John!

[thrifty bill]

Most major truck stops (Loves, Flying J for example) will have on site "CAT" commercial scales.

[gordon2]

Originally Posted by thrifty bill

Most major truck stops (Loves, Flying J for example) will have on site "CAT" commercial scales.

And there are many web sites and web videos that help you know how to use the CAT scales including how to get the weights for a small travel trailer and tug. One thing I learned from them was also half of President Theodore Roosevelt's policy. That is to carry a big stick. It seems that most the CAT scales, being designed for 18 wheelers, have the call button so high as to be out of reach for the average small RV trailer owner. You might be able to find a free scales, but the CAT scales fee is not so bad and generally only needs to be done once or if major changes are made. I have used CAT scales exactly once for each travel trailer I have owned.

[John in Santa Cruz]

or then, you could do what I did.... decide my Tacoma was too close tot he payload limit, and buy an F250 Diesel longbed, that can tow 12500 lbs and/or haul 2000 lbs. I will never ever come close to either of those numbers


What, me worry??