How to get an accurate pin weight

[SDCOToyhaul]

Wondering, how do you get an accurate pin weight? When I went to get everything weighed, the scale was about 50' long. I pulled just far enough onto the scale so that just the landing gear could be lowered onto the scale. Unfortunately, and glad I didn't, I didn't have the toys in the 5'er when I weighed it. Without the toys, have a 3240 weight on the jacks. Had a blow out on the way to the scale so glad I didn't have the extra 1500#s loaded up. The 5'er total weight is 10,800# without the toys, water, or food and etc. Also, another question, has anyone used a device that allows you to pull forward onto the wedge with the good tire and raise the other axle to change out a tire?

[Tony Lee]

Pull the tow vehicle on to the end of the scales so all four wheels are on. Note the weight.
Raise the trailer using the landing gear (obviously landing gear must be on the ground, not the scales.
Note the weight.
Difference is the pin weight.

[andy29847]

How To Weigh | CAT Scale


I weighed all of my rig on the first pass, making sure that my truck was on a different part of the scale than the trailer.

Then I pulled off the scale, unhooked my trailer, and went through the scale again with just my truck.

I was charged $10 for the first pass, $2 for the second one.

[glennwest]

I pull truck, camper on scale. Weigh everything. Go to destination and set up. Then go weigh just the truck my next trip to town.

[wingnut60]

I do it this way on the semi scales--pull on so the truck front axle is on first pad, rear axle on second pad, and fiver on third pad with landing legs just barely on the same pad.
Get a weight reading, then raise the fiver until there is no weight on the truck, get a second reading. Difference on rear axle is pin weight. No unhitching. May not work for all trucks/fivers, but does for my setup.
Joe

[glennwest]

I tried that method and got bad readings. Hard to judge when you just get just the weight off with a ldt.

[Tony Lee]

Originally Posted by glennwest

I tried that method and got bad readings. Hard to judge when you just get just the weight off with a ldt.

Also, if the pin is not exactly over the rear axle, the load on the front axle will also change so the change in load on the rear axle will be different to the pin weight.

[glennwest]

Originally Posted by Tony Lee

Also, if the pin is not exactly over the rear axle, the load on the front axle will also change so the change in load on the rear axle will be different to the pin weight.

????????? When you reweigh it, it get the off load amount. Don't get what you getting at. Even with my 6k pin it isn't a lot.

[JIMNLIN]

I have a small town feed store mill that has a single platform scale. Its open 24/7 so I weigh on sundays or after working hours. Its a hoot to weigh in lots of different situations.

I drive truck on the scales till the trucks back tires are still just off the platform for my first number then pull all the way on for my gross and rear axle weight.
I then hook up the trailer and repeat the process.
I also double check by weighing each axle as I drive off.
I live just down the road seven miles so weighing/hooking and unhooking is no problem

I prefer separate front and rear axle weights for the truck.

[Tony Lee]

Originally Posted by glennwest

????????? When you reweigh it, it get the off load amount. Don't get what you getting at. Even with my 6k pin it isn't a lot.

What I'm getting at is this statement "Difference on rear axle is pin weight." is not correct unless the coupling is exactly over the rear axle. If you are only concerned with what is happening to the rear axle when you hook up the trailer, then your method is fine.
Perhaps my definition of pin weight is different.

[hbillsmith]

To add to WINGNUT, using the second truck only weight, subtract that from the weigh number one's total combined weight. That is your loaded trailers weight. Trailer pin weight, as stated, is the difference between steer axle plus drive axle, weigh #1 vs. weigh #2.

[Gordon Dewald]

Originally Posted by Tony Lee

What I'm getting at is this statement "Difference on rear axle is pin weight." is not correct unless the coupling is exactly over the rear axle. If you are only concerned with what is happening to the rear axle when you hook up the trailer, then your method is fine.
Perhaps my definition of pin weight is different.

Should not matter all that much if the coupling is exactly over or not. The difference will be small unless the distance off the axle is fairly large.

The important part is how the pin weight affects the truck. If the pin is in front of the axle some of the weight will go to the front axle. When you weigh the unit it will give you the actual weights. Does the added weight from the trailer put either the front or the back GAWR over the truck limits? If it does you know the drill.

Same if the pin is behind the axle. If the pin is behind the axle it will move some weight from the front axle to the back axle. When you weight the unit it will give you the actual weights. Does that added weight from the trailer put either the back or the front GAWR over the truck limits? If it does you know the drill?

If you add the front and rear axle loads does it exceed the GVWR? If it does you know the drill.

Important part is to have the truck and trailer loaded with everything you plan to carry normally. Full fuel, family, pets, toys, food, water, etc to get an honest reading.

If you have access to a scale that has a single deck you can weigh the unit by pulling one set of axles on at a time. It is important that the run off at each end is fairly level at both ends.

Pull the unit on from one end and note the weight as each axle pulls on. I would do the same on the other end as you pull off and compare the numbers. So pull the front axle on take the weight of the front axle, pull the rear axle on and the weight increase will be the weight of the rear axle, pull the trailer on and the weight increase will be the weight of the trailer axles. At the other end pull the front axle off and the reduction in weight will be the weight on the front axle (this weight should be similar to the first weight you took pulling onto the scale), pull the truck off and the next reduction will be the weight on the rear axle (similar to the increase in weight when you pulled the truck onto the scale), the weight remaining on the scale is the trailer and should be similar to the third weight increase when you pulled the trailer onto the scale.

Also weigh the unit when you are at the center of the scale to get an accurate total weight. (there are times when there can be a variance on a scale if the load is not centered. It will depend upon the type of scale, the mechanisms and any binding that may occur between the deck and the bumpers.) Compare the accumulated weight at each end of the scale with the total weight in the center. If it is close you can have a lot of confidence the axle weight pulling on and off are good. Also a comparison of the axles pulling on and off should be close.

Seems to be complex but these kind of procedures are used to check scale accuracy during certification. Difference is during certification known weights and loads are used to make sure the scale is weighing correctly.

[glennwest]

I use cat scales. Real simple.

[Dieseljeeper]

Generally the hitch can handle a much larger load than the truck can, the axle weight is what will get you a ticket.