Help with hitch / tongue weight

Unless you're talking about thousands of pounds in the bed aft of the truck's rear axle, you're splitting hairs here guys.

The reality is that any realistic amount of weight in the truck bed is not going to change the front ride height enough to affect your WD hitch settings.

A couple of bikes, a few sticks of firewood, a cooler of drinks... None of that or even all of that is not going to visibly "squat" your truck unless you have some extremely soft springs... Besides you'd have to work hard to get it all crammed in aft of the rear axle.

IDoMyOwnStunts wrote:
The TV rear axle is the fulcrum (pivot point). The entire truck is the lever. The WD system is the upward force applied to that lever behind the rear axle. The weight of cargo behind the rear axle AND the weight of the tongue of the trailer both apply downward forces behind the rear axle. Thus the WD system must apply enough upward force to counter both the weight of the trailer tongue AND the weight of the cargo behind the axle in order to restore weight to the front wheels.

The place where it gets complicated is that you actually have two levers, the other one with the fulcrum at the travel trailer wheels. However, the purpose of the WD system is the same. It is an upward force against that lever and that force still must act against the total downward force applied by both the trailer weight forward of the axles (the tongue) and the cargo behind the rear axle of the TV.

Ok, so why does the receiver rating need to take into consideration the weight of any cargo behind the rear axles? Because it needs to be sized to cope with the counter force applied by the WD system back through the receiver. Even though the WD system may take some weight off the ball, the full force of that WD system is still transmitting through the receiver back to the truck (minus the weight transferred back to the travel trailer tires).

Think about this. If you did not have any trailer hooked up and you loaded cargo behind the rear axle, that will take weight off the front axle. This is simple lever physics. The truck is a seesaw that wants to pivot on that rear wheel. Too much force on the back side of the truck will lift the front wheels off the ground. And weight is a force. Only, in this case, you have no means to restore weight to the front axle other than moving the cargo.

So, the bottom line is that if you want to restore all of the weight taken off the front wheels when you hook up your trailer, you must size and adjust your WD system to account for cargo behind the rear wheels. If you do not, you simply will not restore all of the weight back to the front wheels or you may overload your current system trying to restore that weight. Does it matter? That is entirely up to you. As for me, I felt the need to upgrade my receiver.

Thanks for reading.

Edit to add: Yes, I realize that the springs from the truck and trailer suspension provide upward force as well. That still doesn't change the pivot points nor the forces on the receiver/WD system.

THANK YOU, you have summed up what I've been trying to get across and I agree with everything you have said. For some reason I wrongly assumed that providing what I thought were very VALID and AUTHORTATIVE quotes would clarify things, but for some reason did not.

I would just add that in one of my original posts I tried to acknowledge that just how significant this cargo was to increasing what CEQUENT classifies as "HITCH WEIGHT" because it's position relative to the rear axle of the TV and the hitch head can vary and I believe this has an impact on the actual amount of increase in "HITCH WEIGHT" is realized. I can only WAG that this is basically ignored since assuming all the weight is added is the safest position and in 99.9% of the cases will not cause one to really over specify the sizing of the WDH components. In that document from CEQUENT I linked to has a chart for WDH bar ranges vs this "HITCH WEIGHT", but of course that opens the previous "CAN OF WORMS" about some that feel even using bars rated at just what the actual trailer tongue weighs is overkill and not required.

Finally, as I have said I'm probably a little more sensitive to this since my cargo aft of the axle VARIES by hundreds of lbs even during a trip or between trips and that is why I call the cargo "TEMPORARY" and included with pics the 4 fuel cans, generator, tool box, etc that are sometimes carried empty or full with that varying during a road trip between towing days as an example of this "CARGO ADDED" that I was talking about. Conversely, even with my somewhat unique setup I have significant weight (probably close to 1,000 lbs) between the rear of my Van and the rear axle on my Van that is fairly fixed because of the secure storage area that I built along with the sofa-bed and all the tools/parts, etc. that remain there all the time. This weight is "NOT TEMPORARY" and does not need to be accounted for as this "weight" is included in the normal "LOADED" configuration of my Van, is always there, and already accounted for when the WDH was originally setup and adjusted. Of course by the same token one should adjust their WDH with full fuel, and ensure removable items such as spare tires that are normally on the vehicle are all in place since those IMO are really not cargo as CEQUENT is talking about, but a normal loaded condition of the TV. Regardless, the concept and validity of accounting for this "added cargo" weight to the "HITCH WEIGHT" is still valid IMO and should at least be acknowledged and included where applicable. For one to say it has no effect is IMO incorrect. I think this is why CEQUENT specifically says the weight is "CARGO ADDED" where added is the operative word meaning its after the WDH has been set up for what would be considered a normal "loaded" vehicle configuration and even goes as far as trying to include such what I would classify as transient items such as "gas cans, tools, boat motors, etc" in their classification as types of "cargo added" they are talking about. This would also include say extra baggage and even passengers in the very rear seats of say a large SUV that might be there on some trips, but not others. It could also include those 10 cases of beer stored at the rear of say an SUV for that once a year lake campout, beer party for the office, etc. Another example might be taking a golf cart in the bed of a pickup on some trips, but not others unless one would want to go thru the entire WDH setup routine, adjustment, road testing, etc. every time such "added cargo" like a golf cart was or was not there.

Larry

Ron Gratz wrote:

IDoMyOwnStunts wrote:
The TV rear axle is the fulcrum (pivot point). The entire truck is the lever. The WD system is the upward force applied to that lever behind the rear axle. The weight of cargo behind the rear axle AND the weight of the tongue of the trailer both apply downward forces behind the rear axle. Thus the WD system must apply enough upward force to counter both the weight of the trailer tongue AND the weight of the cargo behind the axle in order to restore weight to the front wheels.

Thanks for joining this discussion.

I agree with your statements. However, there is no consensus on how much load needs to be restored to the front axle. And, there is no agreement on whether it is necessary to restore any of the load which is removed due to TV cargo weight.

For example, Progress Mfg was the first WDH manufacturer to adopt the Front Axle Load Restoration (FALR) approach for adjustment of the Equal-I-zer WDH.
The Equal-I-zer Instructions state:

Step 1 - Set up Location:
Before installing the hitch, the tow vehicle and trailer should be loaded just as they will be while traveling. This includes full propane and fresh water tanks, and any other cargo the tow vehicle (passengers & gear) or trailer will carry, including ATVs for toy haulers. Tow vehicle “auto-level” systems should also be disabled or turned off temporarily. Park the trailer and tow vehicle on level ground and in line with each other. Chock and uncouple the trailer. Pull tow vehicle ahead about 5 feet to allow working area and set the parking brake.
Take the initial setup measurements for the tow vehicle by measuring from the ground to the top of the wheel wells directly above both the front and back axles of the tow vehicle. See figure 18. Record these on line A of the Weight Distribution Adjustments tables in Step 6.

Subsequent instructions state that, when the TT is hitched, the WD should be adjusted to eliminate 50-100% of the front-end rise due to tongue weight only.

Recently-revised instructions for Reese WDHs state:

INITIAL HOOK UP NOTE: Car and trailer should be loaded and ready for travel before final leveling.
1. Pick reference points on front wheel well. Measure and record distance to pavement.
Front wheel well to pavement ___________________

For proper adjustment of the WFH, Reese goes on to state:

Re-measure front wheel well reference point. The front wheel well height should be equal to the original measurement.

For both Equal-I-zer and Reese, the current WDH adjustment specifications are based on the front end load/height changes due to tongue weight only. The WDH adjustment does not compensate for TV cargo weight.

Ron

Thanks. I do see what you are saying. If I have it right, then using those methods described above, you would not be compensating for cargo behind the rear axle because you are preloading the vehicle as you would when camping, then taking the measurements. I just checked and my Ford manual says pretty much the same thing:

When hooking-up a trailer using a weight-distributing hitch, always use
the following procedure:
1. Park the loaded vehicle, without the trailer, on a level surface.
2. Measure the height to the top of your vehicle’s front wheel opening
on the fender. This is H1.
3. Securely attach the loaded trailer to your vehicle without the
weight-distributing bars connected.
4. Measure the height to the top of your vehicle’s front wheel opening
on the fender a second time. This is H2.
5. Install and adjust the tension in the weight-distributing bars so that
the height of your vehicle’s front wheel opening on the fender is
approximately halfway between H1 and H2.
6. Check that the trailer is level or slightly nose down toward your
vehicle. If not, adjust the ball height accordingly and repeat
Steps 2–6.

So, if I follow the manufacturer's recommendation to the letter, I will not be compensating for cargo behind the rear axle since it says "loaded vehicle". Interesting.

IDoMyOwnStunts wrote:
The TV rear axle is the fulcrum (pivot point). The entire truck is the lever. The WD system is the upward force applied to that lever behind the rear axle. The weight of cargo behind the rear axle AND the weight of the tongue of the trailer both apply downward forces behind the rear axle. Thus the WD system must apply enough upward force to counter both the weight of the trailer tongue AND the weight of the cargo behind the axle in order to restore weight to the front wheels.

Thanks for joining this discussion.

I agree with your statements. However, there is no consensus on how much load needs to be restored to the front axle. And, there is no agreement on whether it is necessary to restore any of the load which is removed due to TV cargo weight.

For example, Progress Mfg was the first WDH manufacturer to adopt the Front Axle Load Restoration (FALR) approach for adjustment of the Equal-I-zer WDH.
The Equal-I-zer Instructions state:

Step 1 - Set up Location:
Before installing the hitch, the tow vehicle and trailer should be loaded just as they will be while traveling. This includes full propane and fresh water tanks, and any other cargo the tow vehicle (passengers & gear) or trailer will carry, including ATVs for toy haulers. Tow vehicle “auto-level” systems should also be disabled or turned off temporarily. Park the trailer and tow vehicle on level ground and in line with each other. Chock and uncouple the trailer. Pull tow vehicle ahead about 5 feet to allow working area and set the parking brake.
Take the initial setup measurements for the tow vehicle by measuring from the ground to the top of the wheel wells directly above both the front and back axles of the tow vehicle. See figure 18. Record these on line A of the Weight Distribution Adjustments tables in Step 6.

Subsequent instructions state that, when the TT is hitched, the WD should be adjusted to eliminate 50-100% of the front-end rise due to tongue weight only.

Recently-revised instructions for Reese WDHs state:

INITIAL HOOK UP NOTE: Car and trailer should be loaded and ready for travel before final leveling.
1. Pick reference points on front wheel well. Measure and record distance to pavement.
Front wheel well to pavement ___________________

For proper adjustment of the WFH, Reese goes on to state:

Re-measure front wheel well reference point. The front wheel well height should be equal to the original measurement.

For both Equal-I-zer and Reese, the current WDH adjustment specifications are based on the front end load/height changes due to tongue weight only. The WDH adjustment does not compensate for TV cargo weight.

Ron

The TV rear axle is the fulcrum (pivot point). The entire truck is the lever. The WD system is the upward force applied to that lever behind the rear axle. The weight of cargo behind the rear axle AND the weight of the tongue of the trailer both apply downward forces behind the rear axle. Thus the WD system must apply enough upward force to counter both the weight of the trailer tongue AND the weight of the cargo behind the axle in order to restore weight to the front wheels.

The place where it gets complicated is that you actually have two levers, the other one with the fulcrum at the travel trailer wheels. However, the purpose of the WD system is the same. It is an upward force against that lever and that force still must act against the total downward force applied by both the trailer weight forward of the axles (the tongue) and the cargo behind the rear axle of the TV.

Ok, so why does the receiver rating need to take into consideration the weight of any cargo behind the rear axles? Because it needs to be sized to cope with the counter force applied by the WD system back through the receiver. Even though the WD system may take some weight off the ball, the full force of that WD system is still transmitting through the receiver back to the truck (minus the weight transferred back to the travel trailer tires).

Think about this. If you did not have any trailer hooked up and you loaded cargo behind the rear axle, that will take weight off the front axle. This is simple lever physics. The truck is a seesaw that wants to pivot on that rear wheel. Too much force on the back side of the truck will lift the front wheels off the ground. And weight is a force. Only, in this case, you have no means to restore weight to the front axle other than moving the cargo.

So, the bottom line is that if you want to restore all of the weight taken off the front wheels when you hook up your trailer, you must size and adjust your WD system to account for cargo behind the rear wheels. If you do not, you simply will not restore all of the weight back to the front wheels or you may overload your current system trying to restore that weight. Does it matter? That is entirely up to you. As for me, I felt the need to upgrade my receiver.

Thanks for reading.

Edit to add: Yes, I realize that the springs from the truck and trailer suspension provide upward force as well. That still doesn't change the pivot points nor the forces on the receiver/WD system.

Larry

You're really gonna make my head explode. For newbies reading this, it is NOT this complicated. Tongue weight is the weight placed directly on the hitch ball. Yes, setup your WD hitch with your truck configured/loaded ready to camp. That will make sure your level and have your weight properly distributed as you intend to travel. If you are so close on your margins that you can't put a cooler in the back, then you're probably ready for a truck upgrade. Make sure you have enough margin in your GVWR so if you stop for a Big Mac, you can eat it while driving....

OOps, wait, I might have just started a totally separate argument about eating and driving while towing.

If I see one more personal remark against another member this thread will be history
Barney

No need for yelling Larry. i know your position: you said it so it must be right. If you choose to distribute the aft axle weight in the bed go right ahead, but it is not necessary or required.

Man I miss threads like this! We just don't get good discussions like this on here anymore.
Newbies...read up!

lbrjet wrote:
Larry, your experts simply want to sell you a larger more costly hitch. It is called marketing.

You run your van with weight behind the axle without the trailer hooked up. What you fail to see (or will not admit to see) is that hooking up the trailer ( without shifting that aft weight) is no different than running without the trailer hooked up. That is the whole point. A truck is designed to run with a load in the bed and dropping a trailer on doesn't change that.

IMO this is some of the lamest reasoning I've see thus far. I stated a position on how cargo added after the TV axle should be treated which was agreed with by what I consider who should be EXPERTS in this a major hitch retailer and THE MAJOR manufacturer of three of the most popular systems, REESE, DRAW-TITE, and HIDDEN HITCH and provided clear cites/references to current documentation from them which agree with my position. What you fail to be able to do is to read and understand what I provided and want to create some unsupported rationalization to say they are wrong and try and say it's only marketing to sell us something which it clearly is NOT. They are only giving you the proper way to correctly size you WDH components that you are going to buy anyway.

Your inability to read and be willing to understand what I have said is evident in your understanding of the temp cargo of 20 gal of diesel and the generator and other cargo that normally is not carried except when towing and then not always or in the same position.

I think you are the one that is failing to UNDERSTAND, NOT ME.

Larry