First weigh of truck and AS

[ITSNO60]

Originally Posted by out of sight

A diesel engine and transmission load up the front end quite a bit. When I drop 1000 lbs on the hitch ball I now get even loading on both axles. No weight distribution is necessary. And because I have the full tongue weight on the rear axle the trailer doesn't sway and no sway control device is required.

If you don't restore the front axle weight what does this do to your front alignment being as the trucks are aligned unloaded?

[out of sight]

Originally Posted by SteveSueMac

I have to assume this means something different than the 3 pass method? I don’t know what calculations you did or what process you used on a truck scale to confirm your calculations but if you’re not using WD you’re not using the 3 pass method.

Are you willing to share your scale tickets that show your truck weights ready for camping both solo and then with trailer attached (and obviously no WD)?

I could post them, but what part of my statement do you not believe?

[out of sight]

Originally Posted by ITSNO60

If you don't restore the front axle weight what does this do to your front alignment being as the trucks are aligned unloaded?

The truck is designed to carry a load. Unloaded it is front heavy but fully loaded it's rear end heavy. You want the cargo load on the rear axle, not the front axle. That's why the rear axle has a greater GAWR.

[jcl]

Originally Posted by out of sight

The truck is designed to carry a load. Unloaded it is front heavy but fully loaded it's rear end heavy. You want the cargo load on the rear axle, not the front axle. That's why the rear axle has a greater GAWR.

Yes, but when you have a front end alignment done the truck will be loaded to its usual load. Do you align for empty or loaded?

And note that the truck is designed to carry a load between the axles, not behind the rear axle.

[out of sight]

You can't pull the trailer into the alignment bay but you can sit 3 bubbas on the tailgate when you do the alignment.

[SteveSueMac]

Originally Posted by out of sight

I could post them, but what part of my statement do you not believe?

I just don’t understand what you’re saying. I’m not sure what to believe. I think I’m right in assuming you’re NOT doing a 3-pass scale approach since one of those 3 passes includes seeing the effect of applying WD. So I’m just curious about what the scale tickets are saying and how they confirm your calculations (whatever those are).

You also claim that 78-79% of GAWR on steer and drive axles is balanced. But surely your drive axle has a higher GAWR than your steer does - so I have to assume your steer axle weighs less than your drive axle when you attach the trailer. I don’t understand how that’s balanced. Showing your scale tickets would demonstrate exactly how much weight comes off your steer axle and how much weight is added to your drive axle by attaching the trailer.

It’s not a question of what I do or don’t believe in your statement - I just don’t understand what the heck you’re talking about. Post the tickets so I can see your point, please and thank you.

[out of sight]

Yes. My drive axle GAWR is 6500 and my steer is 6000. Scale with is 5120 and 4680.

You can easily calculate this if you know your axle base weights, tongue weight, wheel base and distance from axle to hitch ball.

[out of sight]

Sorry, scale with trailer attached is ...

[SteveSueMac]

Originally Posted by out of sight

Yes. My drive axle GAWR is 6500 and my steer is 6000. Scale with is 5120 and 4680.

You can easily calculate this if you know your axle base weights, tongue weight, wheel base and distance from axle to hitch ball.

You understand that I of course would have no insight to those data points on your specific truck and that’s why I’m asking what the heck your tickets show, right?

We now know your GAWR for your two truck axles and what you say they weigh with the trailer attached. What do your axles weigh WITHOUT the trailer attached?

Did you lose your copies of the scale tickets?

[out of sight]

3240 drive, 4760 steer.

[jcl]

Originally Posted by out of sight

Yes. My drive axle GAWR is 6500 and my steer is 6000. Scale with (trailer attached) is 5120 and 4680.

Originally Posted by out of sight

(Without the trailer attached) 3240 drive, 4760 steer.

So the truck scales at 8000 lbs without the trailer, and 9800 lbs with the trailer attached? That is quite a tongue weight. And despite 1800 lbs of tongue weight, the front axle was only lightened by 80 lbs? Or are the two weights including other variables as well?

[SteveSueMac]

Originally Posted by out of sight

3240 drive, 4760 steer.

Wait - that means your 28’ AS (in your profile - assuming you’re not talking about your 22’ AS?) has an 1800# tongue? That can’t possibly be the recommended 10% to 15% of the trailer weight or you’d have a 12,000# to 18,000# Airstream! I suppose that could be 24% of the GVWR of your trailer which I assume to be 7600# - but if so, and you’re not including a heavy Hensley on your a-frame, just how many gold bars are you carrying at the front end of your trailer when you go camping? [emoji3]

And what factors do you suppose lead to an 1800# tongue weight lifting only 80# off your steer axle when dropped on the ball of your truck? I honestly don’t recall the formula to calculate the leverage and derive distance from axle to ball and so forth but those numbers are just a total surprise. I’m certain if we did a distribution of all the scale tickets posted in Airforums, your tongue weight and its impact on steer axle would both be several standard deviations out. I’m not saying it’s impossible - I’m just trying to process your numbers.

Were your tickets for the truck then truck+trailer taken the same day? If not, differences in loading, passengers, fuel, gold bars day 1 vs day 2 etc. could potentially explain some element of these surprising results.

This is why I’ve asked several times now for you to kindly just post the blessed tickets. It’s impossible to have a meaningful conversation about this without a common base to work from. Would you care to post the scale tickets please?

[out of sight]

Tongue weight 980, passengers and cargo 820.

So you don't believe the numbers. Could it be because they prove I'm right and that there is no need for a weight distribution hitch? Note also that because I carry the full load on the rear axle the trailer does not sway. But I wouldnt expect you to admit that either.

[out of sight]

The front axle only has 80 lbs lifted off due to the 980 tongue weight. One of the reasons for that is that by towing on the ball the distance to the axle, and the leverage, is minimized. A wd hitch can add a foot to that distance and the leverage is increased. Also by increasing that distance the sway stability worsens.

[Bill M.]

I do not see how more load on the rear axle reduces trailer sway? The truck pivots on the rear axle and affects the steering which causes increased sway. More load might keep the rear end from sliding but I do not see how it reduces the sway forces?

[out of sight]

I think you answered your own question. There will always be forces that try to make the trailer sway but the load on the tires will keep the hitch point from trying to move and that will prevent the sway forces from swaying the trailer. It's similar to what a friction hitch does only now the tire friction is doing it.

If you remove load and friction force from the rear tires with a wd hitch you will now have to compensate with a sway control device. Better to tow on the ball, as long as your vehicle axle can take the load.

The tires play an important part in this, too. I keep my rears at 80 PSI when towing.

[jcl]

Originally Posted by out of sight

I think you answered your own question. There will always be forces that try to make the trailer sway but the load on the tires will keep the hitch point from trying to move and that will prevent the sway forces from swaying the trailer. It's similar to what a friction hitch does only now the tire friction is doing it.

If you remove load and friction force from the rear tires with a wd hitch you will now have to compensate with a sway control device. Better to tow on the ball, as long as your vehicle axle can take the load.

The tires play an important part in this, too. I keep my rears at 80 PSI when towing.

You continue to ignore the contribution of the distance from the TV rear axle to the hitch in terms of contributing to instability and sway. It has been pointed out before.

The TV rear tires you are relying on to resist lateral forces are not located where the lateral loads on the hitch are applied. That lever is what contributes to sway. If you want the rear tires of the TV to resist lateral forces you need to move to a 5th wheel trailer. Or use a 3P hitch.

You can also do the math and see that your 980 lb tongue weight is lifting the front axle much more than the 80 lbs you claim. You appear to be loading your cargo towards the front of the tow vehicle to offset the hitch load. One issue is that you are only considering the static vertical load of the tongue weight, not the dynamic loads, consideration of which is key to a safe setup.

[out of sight]

Scroll up. I did mention the distance to the axle, and how a wd hitch increases it, contributing to sway.

[SteveSueMac]

Originally Posted by out of sight

Tongue weight 980, passengers and cargo 820.

So you don't believe the numbers. Could it be because they prove I'm right and that there is no need for a weight distribution hitch? Note also that because I carry the full load on the rear axle the trailer does not sway. But I wouldnt expect you to admit that either.

I’m not sure if it’s you or I who has the reading comprehension problem here. I can’t decide what to believe about your numbers yet because I don’t yet understand them. Let’s be clear about that point.

If you would just post the tickets here it would be so helpful. I think I’ve been clear about that. Is there anything in that ask that requires clarification?

I think you may be measuring things incorrectly on the scales. You mention 2 different numbers - one for tongue and one for cargo which combined are 1800# - but that wouldn’t produce the results in your numbers if you completed 2 of the 3-pass weights on the scales as described in that method. Again, absent the tickets, how are we supposed to have this conversation??
Perhaps you weighed the truck empty then loaded it up for camping, hooked up the trailer and found a different number? Post the tickets, describe your process. Without knowing those facts, there’s really nothing to discuss. Why is this so difficult??

[SteveSueMac]

Originally Posted by out of sight

The front axle only has 80 lbs lifted off due to the 980 tongue weight. One of the reasons for that is that by towing on the ball the distance to the axle, and the leverage, is minimized. A wd hitch can add a foot to that distance and the leverage is increased. Also by increasing that distance the sway stability worsens.

Again. For the love of camping - POST THE TICKETS!!!!


Your last set of numbers says you have an 1800# tongue. Post the tickets. Describe your process. Then we can unpack what you’re seeing.

And for comparison’s sake - my 980# tongue lifts 460-480# off the steer axle of my 3/4T diesel truck. Different brand than yours yes - but that’s quite a difference. Post the tickets. Describe your process. Then we can actually talk.

Why is this so difficult??