WDH question

[Bowfreak]

I have read several post on WDH and how to set them up as well as youtube videos. The one thing they don't mention is if you are supposed to have your truck loaded with the extra stuff you are going to carry in the cab and/or bed before you set you ball height and take your front and back measurements on the vehicle. I would assume you would want your tow vehicle empty when you set your ball height and take fender wheel measurements. But that would seem like then the pull up bars are transferring more than just the tongue weight as to get it back to level they would be pulling up the extra bed cargo weight as well. If that is correct you would do the initial ball height and measurements while the truck is dry. Then add the approximate amount of payload you are going to carry and adjust the WDH angle and amount of links needed to get the trailer and vehicle back to level?

[Ron_Gratz]

Bowfreak wrote:
I don't think I said anything about getting my truck level.---

Sorry, I misinterpreted the last sentence of your first post.

---I was assuming the front and back would be the same offset if I had it adjusted correctly, just both a little lower due to added weight. So if the front fender was 28" and he rear fender was 30" prior to loading I was assuming that I would want the front 2" lower than the back after loading.

Thanks for the clarification. I always recommend against trying to achieve the same offset (a.k.a. "equal squat").

I believe the reason Ford, GMC/Chevrolet, Toyota, Ram, Equal-i-zer, Reese, and others have abandoned the "equal squat" approach is pretty well summed up in this Letter to Editor by Richard H Klein, P E printed in TRAILER BODY BUILDERS Magazine. The comment which specifically addresses WDH adjustment is:

QUOTE
2. The statement “too much tongue weight can force the truck down in the back, causing the front wheels to lift to the point where steering response and braking can be severely decreased” is not the real issue with heavy tongue weights. The real problem is that the tow vehicle's yaw stability, as measured by “understeer gradient”, is severely decreased. This increases the propensity of the tow vehicle to jackknife in turning maneuvers. Specifically, recent full scale testing conducted by the SAE Tow Vehicle Trailer Rating Committee (and now published in SAE J2807), determined that the use of weight distributing hitch torque should be minimized. In fact they recommend that the Front Axle Load Restoration (FALR) not exceed 100% (100% means that the front axle weight is brought back, via weight distribution, to a weight equal to its “no trailer” condition).
UNQUOTE

A related explanation from a representative of the company which manufactures the Equal-i-zer hitch was first posted here . It says:

QUOTE
In the past we had suggested that you should see a small drop on the front suspension. We are always trying to improve things here at Progress – our motto is “Safe and Happy Customers,” and so we are always reviewing our instructions and installation process. Recently, as part of this constant effort our engineers looked more deeply into this aspect of installation. We had always felt that a small drop was a sign that the trailer’s weight was being transferred to the front axle, and that this was essentially a good thing.

As our engineers reviewed the instructions for the last round of renewal of our instructions, the found research results that contradicted our prior thinking. There has been a substantial amount of testing conducted by experts from SAE and the RV Industry Association to find out what will produce the best stability when towing. This towing suggests that you want your front axle’s compression to be close to, but not lower than your free-standing height.
UNQUOTE

I know I am over thinking this but there is so much conflicting information out there and I haven't seen one document that tells you if you should take your measurements prior or after the TV is loaded. They all mention making the travel trailer the weight you plan on it being when loaded.

The Equal-I-zer OWNER'S MANUAL states the following which I included in a previous post:

"

While installing or adjusting 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 (passengers & gear) the tow vehicle or trailer will carry, including ATVs for toy haulers.

"
(Underline added for emphasis.)

To me if the end goal it to get your tow vehicle back to normal ride height ratio so it handles the same with or without the trailer then you would need to take the measurements prior.---

You previously referred to "prior or after the TV is loaded". Are you talking about all of the load (occupants, cargo, WDH, etc.) or are you talking only about load added in the bed area?

If you put 300# in the bed, how much of it would be behind the rear axle? Even if you placed all 300# with its center of gravity 2' behind rear axle, it would remove only about 50# from the front axle -- not enough to offset the weight of just one adult in the front seat.

---So if I throw 300 - 400 lbs in the bed of the truck and it sinks the rear end and raises the front end that would already cause it to handle worse before I attached the trailer to it. Which would make me think that the WDH would take the tongue weight and some of the bed load weight to help get it back to the pre loading ratio heights.

The current Tacoma Owner's Manual says:
"

If using a weight distributing hitch when towing, return the front axle to the same weight as before the trailer connection.
If front axle weight cannot be measured directly, measure the front fender height above the front axle before connection. Adjust weight distributing hitch torque until front fender is returned to the same height as before connection."

Let's assume you follow Toyota's instructions without any load in the bed and end up with the same front axle weight before and after hitching.
Then you add 300# to the bed = with 150# centered 2' ahead of the rear axle and 150# centered 2' behind the rear axle.
The added 300# will not cause any weight change on the front axle because the portion in front of the rear axle balances the portion which is behind the rear axle.
The 300# only adds load to the rear axle, and Toyota is not concerned about that -- unless it causes the rear GAWR to be exceeded.
If more weight is ahead of the rear axle than behind it, the added weight will cause load to be added to the front axle

IMO, you're overthinking it.
Based on Toyota's WDH instructions, they do not appear to be at all concerned about the before and after height/loading ratios.
Weigh the unhitched TV fully loaded (including the WDH in the receiver and load in the bed).
Then attach TT and adjust the WDH per current Toyota instructions to return the front height to the unhitched value.
If you get the front end right -- the rear end will take care of itself.

Trucks are intended to sag in the rear when loaded.
If it sags more than you want, add air bags but be aware that adding air to the bags after the WDH is adjusted will change the load transfer.

Ron

[mtofell1]

My experience with several different truck/TT and WDH combinations has been that you'll get a feel for the right link to set it at. Some of it, of course, comes from the visual setup but a lot is also just the way it drives. I've found if I set it too tight my rear tires will lose traction on wet pavement when on bouncy terrain. Not tight enough and the chains require no effort to set. If you're bordering on overloading if/when you go too loose the back of your truck will sag. Some trial and error is the best teacher.

[Bowfreak]

Thank you.

I don't think I said anything about getting my truck level. My truck doesn't sit level without anything in it so I wouldn't expect the WDH to make it level after setting it. I was assuming the front and back would be the same offset if I had it adjusted correctly, just both a little lower due to added weight. So if the front fender was 28" and he rear fender was 30" prior to loading I was assuming that I would want the front 2" lower than the back after loading.

Tacoma's are notorious about being soft in the rear to begin with so when I added my camper shell it really sagged the back end so I added some 1500 lb helper springs which helped a bunch.

I know I am over thinking this but there is so much conflicting information out there and I haven't seen one document that tells you if you should take your measurements prior or after the TV is loaded. They all mention making the travel trailer the weight you plan on it being when loaded.

To me if the end goal it to get your tow vehicle back to normal ride height ratio so it handles the same with or without the trailer then you would need to take the measurements prior. So if I throw 300 - 400 lbs in the bed of the truck and it sinks the rear end and raises the front end that would already cause it to handle worse before I attached the trailer to it. Which would make me think that the WDH would take the tongue weight and some of the bed load weight to help get it back to the pre loading ratio heights.

Ron Gratz wrote:

Bowfreak wrote:
What I am worried about is if I set the ball height on the hitch with noting in the bed of the truck, then load the bed for travel and hook up the trailer I will actually be lifting the tongue weight and the bed weight on the WDH. That would seem like a lot of weight for the WDH to equalize out. Assuming 300 lbs or so of weight in the bed of the truck and around 400 lbs on the tongue.

I know I am probably over thinking this I just want to do what is correct and get it as close to perfect as possible.

The ball height should be set with the TV loaded as close to possible to how it would be loaded when ready for camping.
The correct ball height will make the TT close to level when sitting on a level surface (or parallel to a non-level surface).

The purpose of a WDH is to remove some or all of the load which is removed from the TV's front axle by the weight of the tongue.

The current Tacoma Owner's Manual says:
"

If using a weight distributing hitch when towing, return the front axle to the same weight as before the trailer connection.
If front axle weight cannot be measured directly, measure the front fender height above the front axle before connection. Adjust weight distributing hitch torque until front fender is returned to the same height as before connection.

"

Please note that Toyota does not say anything about making the TV "level" nor do they say anything else about rear-end height.

IMO, Equal-I-zer, of all the WDH manufacturers, gives the best specification for loading of the TV before the reference front height is measured:
"

While installing or adjusting 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 (passengers & gear) the tow vehicle or trailer will carry, including ATVs for toy haulers.

"

A WDH should NOT be used to compensate for weight of TV cargo.

If you feel that your TV must be "level" for appearance reasons, you can install air bags.
Then you can learn how to use the air bags in conjunction with the WDH so the front end is returned to the correct load/height and the TV is "level".

If "level" is important to you at other times, the air bags also can be used to compensate for TV bed load when not towing.

Ron

[Ron_Gratz]

Bowfreak wrote:
What I am worried about is if I set the ball height on the hitch with noting in the bed of the truck, then load the bed for travel and hook up the trailer I will actually be lifting the tongue weight and the bed weight on the WDH. That would seem like a lot of weight for the WDH to equalize out. Assuming 300 lbs or so of weight in the bed of the truck and around 400 lbs on the tongue.

I know I am probably over thinking this I just want to do what is correct and get it as close to perfect as possible.

The ball height should be set with the TV loaded as close to possible to how it would be loaded when ready for camping.
The correct ball height will make the TT close to level when sitting on a level surface (or parallel to a non-level surface).

The purpose of a WDH is to remove some or all of the load which is removed from the TV's front axle by the weight of the tongue.

The current Tacoma Owner's Manual says:
"

If using a weight distributing hitch when towing, return the front axle to the same weight as before the trailer connection.
If front axle weight cannot be measured directly, measure the front fender height above the front axle before connection. Adjust weight distributing hitch torque until front fender is returned to the same height as before connection.

"

Please note that Toyota does not say anything about making the TV "level" nor do they say anything else about rear-end height.

IMO, Equal-I-zer, of all the WDH manufacturers, gives the best specification for loading of the TV before the reference front height is measured:
"

While installing or adjusting 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 (passengers & gear) the tow vehicle or trailer will carry, including ATVs for toy haulers.

"

A WDH should NOT be used to compensate for weight of TV cargo.

If you feel that your TV must be "level" for appearance reasons, you can install air bags.
Then you can learn how to use the air bags in conjunction with the WDH so the front end is returned to the correct load/height and the TV is "level".

If "level" is important to you at other times, the air bags also can be used to compensate for TV bed load when not towing.

Ron

[Bowfreak]

What I am worried about is if I set the ball height on the hitch with noting in the bed of the truck, then load the bed for travel and hook up the trailer I will actually be lifting the tongue weight and the bed weight on the WDH. That would seem like a lot of weight for the WDH to equalize out. Assuming 300 lbs or so of weight in the bed of the truck and around 400 lbs on the tongue.

I know I am probably over thinking this I just want to do what is correct and get it as close to perfect as possible.

[3oaks]

goducks10 wrote:
It is kind of a conundrum when setting up the TV and TT. That's why dealers never get it right. The TT is usually empty as well as the TV. JMO but I'd set it up whichever way is convenient. If after you get it all loaded and it's not right then grab an extra link. I've never completely loaded my TV and or TT as if camping and setup the WD. If it needs some tweaking you could always adjust on the fly. I've stopped before in a parking lot and added a washer or grabbed another link......................................

I agree. That is just what I do also.

Another point for the O.P. to think about. Every last pound is not that critical. How many start out with a full tank of fresh water and don't even consider tinkering with the WDH as they consume the water and empty their waste tanks along the way to their final destination. It's not necessary, that's we don't.

[goducks10]

It is kind of a conundrum when setting up the TV and TT. That's why dealers never get it right. The TT is usually empty as well as the TV. JMO but I'd set it up whichever way is convenient. If after you get it all loaded and it's not right then grab an extra link. I've never completely loaded my TV and or TT as if camping and setup the WD. If it needs some tweaking you could always adjust on the fly. I've stopped before in a parking lot and added a washer or grabbed another link.
Just remember to use the tongue jack to raise and lower the tongue to make snapping up the chains/bars easier. If you're not needing to raise the tongue to snap up the chains/bars then you're not putting enough tension on the spring bars.

[Ron_Gratz]

The installation instructions provided by most WDH manufacturers are woefully out of date and/or woefully inadequate when it comes to whether the tow vehicle should be loaded as for camping.

Eaz-lift have been selling WDHs since the early 1950s and their installation instructions seem to be written for "cars" to which they refer several times.
Eaz-lift states: "Measure towing vehicle before adding load to towing vehicle."

Equal-I-zer (whom I consider to have the most up to date instructions) is much more specific: "While installing or adjusting 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 (passengers & gear) the tow vehicle or trailer will carry, including ATVs for toy haulers."
Equal-I-zer was the first WDH manufacturer to abandon the "equal squat" approach toward WDH adjustment.

IMO, the WDH should NOT be used to compensate for any of the load carried in the TV.

Also, most major TV and WDH manufacturers now specify that the WDH should NOT be adjusted to make the TV "level".
Instead, they specify that the front end height, with TV attached and WD applied, should never be less than the unhitched height.
Some manufacturers specify that only 50% of the front-end rise should be eliminated, and some specify a range of 50-100%.

Ron

[Golden_HVAC]

You are putting way more effort into this than required.

I would load the truck to the normal weight, then set it up for towing, with the fresh water tank full on the trailer.

If you have a 3/4 ton or 1 ton truck, the WD bars really do not need to take a lot of the load, and you do not need to worry so much about returning the front axle bumper height back to normal. Just add some pressure to the bars, and it will all work out fine. If you really overtighten the bars, it will act like a spring, and handling will be worse than if not connected at all!

Once you think you have it set OK, then raise the trailer with the jack about 6" (with the ball locked onto the truck) and you will notice that the bars now are loose, and easy to attach and remove. Mark them so that you do not install them to tight.

My buddy saw the camper next door try to remove his WD bars while under a LOT of pressure and dislocate his arm, then learned how to do it right, with very little effort at all! He also bought a electric jack for Christmas to make hitching up to his 3/4 ton Suburban really easy.

Good luck,

Fred.