How Important is able GAWR

[boggs]

I'm about to pick up a 2017 Lance 2375. Everything is in spec with my truck. I have over 1k pounds available payload after my wife and I are in the truck with a full tank of gas. 6500 GVWR on the trailer will be 975 lbs hitch guesstimating at 15%.

My question is about the axles. My front axle shows a GAWR OF 3450 lbs. Cat scale shows 3060 at the front axle. How much weight does a WDH push to the front axle?

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[HammaMan]

Full tank of gas is already factored into payload. WDH adds what you want it to as it's adjustable. Weigh your truck before going to the dealer to pick it up and then right after so you're sure exactly what you're working with.

 

[Buyer2021]

Full tank of gas is already factored into payload.

My question is about the axles. My front axle shows a GAWR OF 3450 lbs. Cat scale shows 3060 at the front axle. How much weight does a WDH push to the front axle?

Unlikely you'll have a problem, IMO. Maybe close, but not likely to exceed.

Adjust the WDH properly with the truck and trailer 'loaded for travel' and then verify with another CAT scale run with the WDH engaged. Let us know how it turns out.

15% tongue weight (loaded for travel, WDH not engaged) is a good target, IMO, for ensuring sway-prevention. Make multiple passes at the Cat Scale (truck alone, truck+trailer with WDH NOT engaged, truck+trailer with WDH engaged) to get all the data you need to determine all of your critical weights / weight bias.

Take a bit of time, pay a few bucks, gain knowledge of your rig's real weight / weight bias situation ..... priceless, IMO.

 

[Aron]

How much weight does a WDH push to the front axle?

It depends upon the WDH setup you have. Mine (Blue Ox Sway Pro) uses spring bars connected to the trailer A-frame with chains, so depending upon how tightly I hitch up the chains will effect how much weight is imparted upon the front axle (and trailer axles). It also depends upon the stiffness of the spring bars I have included (mine are 1000lb bars for a ~900lb hitch weight).

Other WDH setups only have one setting, so will have a static amount transferred. The WDH instruction manual (or manufacturers website if you don't have the manual) should explain how to install your WDH, and should probably explain what weight should be imparted upon the other axles. They do this primarily so that you can match your WDH with your weight distributing needs--while you don't want an undersized WDH for obvious reasons, you also don't want an oversized WDH, since that will impart too much weight on the front and trailer axles, and in general make for a poor towing experience.

 

[Ed21]

My setup with my 5800# loaded TT. WDH adds 20# to my front axle, if that helps.

 

[Aron]

My setup with my 5800# loaded TT. WDH adds 20# to my front axle, if that helps.

I don't want to get into your business, but if that statement is correct, it doesn't seem like your WDH is set up correctly (or it's undersized for your needs, or your trailer is not balanced correctly). A properly balanced travel trailer should have 12-15% of the total trailer weight on the hitch, so in your case 700lbs - 870lbs. A WDH distributing that much load should impart more than 20lbs onto the front axle. (I can't say for certain exactly how much more, since it will depend upon a number of factors.) If it's only moving 20lbs from the rear axle to the front axle (and probably another ~20lb from the rear axle to the trailer axles), that's probably not worth the weight penalty of the WDH itself, and it certainly doesn't sound like it's doing the job it was designed for.

 

[Ed21]

I don't want to get into your business, but if that statement is correct, it doesn't seem like your WDH is set up correctly (or it's undersized for your needs, or your trailer is not balanced correctly). A properly balanced travel trailer should have 12-15% of the total trailer weight on the hitch, so in your case 700lbs - 870lbs. A WDH distributing that much load should impart more than 20lbs onto the front axle. (I can't say for certain exactly how much more, since it will depend upon a number of factors.) If it's only moving 20lbs from the rear axle to the front axle (and probably another ~20lb from the rear axle to the trailer axles), that's probably not worth the weight penalty of the WDH itself, and it certainly doesn't sound like it's doing the job it was designed for.

Thanks for the input. It’s currently set up by taking the measurements at the top of the wheel wells like Ford recommends for setting up a WDH and the measurements are spot on. I have no problems towing with sway or porpoiseing. No abnormal tire wear or steering problems in 10,000 miles of towing. Are you saying Fords instructions are wrong?

 

[Aron]

Thanks for the input. It’s currently set up by taking the measurements at the top of the wheel wells like Ford recommends for setting up a WDH and the measurements are spot on. I have no problems towing with sway or porpoiseing. No abnormal tire wear or steering problems in 10,000 miles of towing. Are you saying Fords instructions are wrong?

No, it sounds like it's all working out for you. However, a WDH should transfer more than about 40lbs from the rear axle to the front/trailer axles, so something sounds off. Based on what you've said above, my leading guess at the moment is that the scales were off when you did either the beginning or final weight measurements, because it sounds like you did everything correctly and it's towing properly. But that 20lb number just doesn't fit everything else that you've said.

 

[Ed21]

No, it sounds like it's all working out for you. However, a WDH should transfer more than about 40lbs from the rear axle to the front/trailer axles, so something sounds off. Based on what you've said above, my leading guess at the moment is that the scales were off when you did either the beginning or final weight measurements, because it sounds like you did everything correctly and it's towing properly. But that 20lb number just doesn't fit everything else that you've said.

Certified Cat scale. Also set up per Husky Centerline instructions. Just curious what you base your numbers on. Just want to make sure I’m covering all the bases. I welcome advice, it’s all good.

 

[Aron]

Certified Cat scale. Also set up per Husky Centerline instructions. Just curious what you base your numbers on. Just want to make sure I’m covering all the bases. I welcome advice, it’s all good.

Physics and engineering math. The principle is all based upon the concept of levers that we learned as kids: all of the relevant distances x forces must equal. The force of the moment imparted by the twisting action created by hooking up the WDH lifts weigh from near the WDH (rear axle) and redirects it to the outer points (front and trailer axles) in proportion to the distances of those axle points to the fulcrum (in this case, the WDH).

If you're loading 700-870lbs onto the hitch, with a normal hitch (without weight distribution) that load should increase the weight carried by the rear axle to somewhere around 1000lbs more than you started with, and decrease the weight on the front axle by a few hundred pounds. The extra weight behind the rear axle of the vehicle changes the balance of the whole truck and forces the rear axle to carry an even bigger portion of the truck's weight than just the added trailer weight, while at the same time lifting the front of the truck some.

A WDH should take that 700-870lb hitch weight and spread it over all three load carrying points (front axle, rear axle, and trailer axles). I would guess that after everything is hooked up, that all three axle points would each be carrying 200-300 lbs more than what they were before the trailer was hooked up, distributed more or less evenly. (The exact proportion that each axle point carries will differ a bit on each truck/trailer setup depending upon the distance between the two truck axles, the distance from the rear axle to the WDH, the distance from the WDH to the trailer axles, and the strength of the WDH moment force. For example, a setup with a short wheelbase truck and a really long trailer would probably end up with more weight on the front truck axle than the trailer axle due to balancing of the lever moment arms, as compared to a long wheelbase truck and a short trailer.) This is why your 20lb front axle number raised a red flag for me--I would expect it to be somewhere around a third of 12-15% of 5800lbs (in the neighborhood of 200-300lbs).

Also remember that CAT scales are calibrated to accurately weigh 30-40 ton trucks; at the "light" end where we're concerned, those scales can be off by even a few hundred pounds without really trying, and probably still within certification limits. That being said, CAT scales are still probably the most accurate method of weighing our trucks that most of us gererally have access to, so I would recommend continuing to use them. Just be aware that they might be off a bit when only measuring a few tons. In the same way that you wouldn't expect your bathroom scale to be able to precisely measure a few ounces.

 

[UGADawg96]

From just going from 5 threads to 7 threads on my Andersen WDH with a 6500lb travel trailer, I am able to move 100lbs to the front axle and 40lbs to the trailer axle while lightening up the rear axle 140lbs. This is all while measuring less than 1/4" difference to the front wheel wells.

I think you need to capture the wheel wells unloaded, with the trailer, and then with the WDH engaged. Then do all the same on the CAT scales listing the steer, drive, and trailer weights. Only then will you know how dialed in you are and how well the WDH is doing.

 

[Cobraman428]

Follow your WDH instructions on setup and make sure you set your truck using the Ford setup. Get the 2023 Ford Towing guide....

 

[HammaMan]

Pics?

 

[Ed21]

Follow your WDH instructions on setup and make sure you set your truck using the Ford setup. Get the 2023 Ford Towing guide....

I did primarily use this guide along with the hitch manufacturers instructions. I’m going to go through everything again to recheck everything using the information you guys have provided and see where there’s room for improvement. Thanks for the input. Unfortunately the cell signal is too weak to include a picture. Will send that later.

 

[Ed21]

Only pic I have.

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