What does a WD hitch do?

[Toasty's Dad]

I'm trying to figure out if and if so why I need a WD hitch.

When I weigh my loaded trailer / truck combo on a CAT scale, I come up with 260 lbs difference between the front and rear axle. The loaded weight of the truck unhitched is 4820, and the loaded+hitched weight is 5340.

The 260 lb difference is much less than 10% of truck's of weight.

So, given the relatively small weight difference, do I still need a WD hitch? If so, why?

Is it because that 260 lb difference needs to be eliminated to be safe? If so, then just what is a tolerable difference in weight between the front/rear axle? There must be _some_ tolerable limit, because the trailer is unlikely to be loaded identically from one trip to the next, and because the adjustments aren't fine enough to be made to the pound.

Or is there something else a WD hitch does for me in a panic situation that mandates its use?

I wanna get this puppy in to the hitch people for sway control this week, and I'm trying to figure out why I should tell them to install WD also. FWIW, the truck manufacturer (Honda) specifiically recommends _against_ using a WD hitch in the owner's manual.

Thanks again,
jon

[Silvertwinkie]

It's my understanding that weight distribution takes the hitch weight of the trailer and shares that weight with both the tow vehicle and the trailer.

Not sure which Honda you have, but if it's got a soft suspension, the lowest possible weight bars might be needed to help get the truck and the trailer near level when towing. It's hard to guess what would happen since the 16' is such a small load and not knowing what Honda you are talking about.

Another bi-product of weight bars can be sway control too, where the sway controls are mated to the sway bars, but in the case of a 16' unit, regular friction sway control would be what I'd do since most hitch places I spoke with said that around 25' is when you'd go with a dual cam type sway. Additionally, the adding weight bars does add some rigidity to the connection between the tow vehicle and the trailer. This could be helpful, particularly with emerg manuvers.

Not sure if the 16' has electric brakes, but if it does, I'd make sure they are connected to a good brake controller.

[Toasty's Dad]

Hello Silvertwinkie,

It's a Honda Ridgeline; dunno it it's suspension would be considered "soft", but it sure isn't as smooth as my car's!

On one hand, I've got my truck owner's manual telling me _not_ to do WD, the hitch place telling me I might not need to do WD, and my CAT scale numbers plus what rule-of-thumb info I've found on the Forums telling me that I don't particularly need to do it.

On the other hand, I've got most of the people on the Forums telling me that I'm in deep doo-doo if I don't. But I've been waiting for somebody to explain just what the WD will do that will save my butt in my particular towing situation, which is somewhat different from many others', given the tiny trailer and relatively large TV.

Your post has given me something to really sink my teeth into:

>Additionally, the adding weight bars does add some rigidity to the connection >between the tow vehicle and the trailer. This could be helpful, particularly with >emerg manuvers.

I will add this WD favorable info as a major data point into my deliberations.

And again, with or without WD, I'll be doing _at least_ friction sway control.

THANKS!
jon

[crazylev]

If I am not all ferklempt, I'm pretty sure that WD places the weight of the tongue of the trailer evenly over the four wheels of your tow vehicle. This reduces the downward force/weight at the point of connection, the hitch ball.

The example I remember is with the weight bars, you have in effect a wheel-borow. The weight is distributed outward toward the person operating the wheel borrow.

I think this gets into geometry and or physics, both of which I suck at. Thus the reason why I spent four years as at art school instead of Yale.

I learned everything about this subject on these forums, so maybe try a search.

Cheers.

Jonathan

[bryanl]

Believe the manual that comes with your tow vehicle and follow its advice and recommendations.

The purpose of a weight distributing hitch is to prevent a rear squat that adversly impacts tow vehicle handling. The primary cause of handling problems is the lifting of the front axle which reduces steering capability.

If your tow vehicle suspension can prevent the rear squat and keep a proper weight on the steering axle, then a weight distributing hitch isn't really needed. This is often the case on long wheelbase pickup trucks with a short overhang (little leverage for the ball to pick up the front and a heavy duty suspension). It is also the case on some of the newer vehicles with active suspensions. You do need to make sure the receiver is properly specified as they will usually handle more with WD than without.

I disgree with the emergency ideas on weight distribution being a safety issue. Yes, they are a spring in the middle of your rig that does what most suspension springs do. But no, they aren't a major influence in an emergency situation. What you worry about in emergency situations is the weight of the trailer pushing the tow vehicle around. The primary fix for this is good trailer brakes (and staying out of such situations by being an aware driver).

Of course, if your steering gets squirrely, you don't need an emergency to have problems!

I also think you should tackle sway first by noting if the handling down the road really requires improvement. Start by making sure you have good tires with stiff sidewalls inflated to max sidewall psi and proper rig loading.

There is no cut and dried solution that works in all cases for all rigs. What you are after is good handling that allows a driver to be comfortable and keep control of the rig. There is no magic recipe that will eliminate all risk and no one solution that works for all cases.

[funchucky1]

Hey, Jon. Tough situation.
Ultimately, a weight distribution system does just what the name implies - it distributes weight-- between the front and rear wheels of the tow vehicle.
Without it, all of the tongue weight sits on your hitch.
This does a few things - drops the rear of the tow vehicle, raises the front of the tow vehicle (possibly enough to affect steering and handling negatively, makes your headlights aim to high, reduces your ground clearance....most of all, it makes your vehicle handle poorly, especially in panic situations.

That all said, you say your owners manual says no to a WD system. If it says "not recommended," that's one thing. If it says, "No," then you may have to deal with the dealer trying to blame your setup for any future failures while towing, or failures of the frame, the hitch, the suspension, or even the drivetrain (and then they will not honor warranty work for these things). Yes, there are other things involved...they may have to PROVE that your towing setup was to blame, but at the least, it's a huge hassle. (Of course, there are many people who would ask, "why would the dealer ever have to know how I tow??")

Ultimately, look at the numbers to see if it's even reasonable to tow without a W/D setup.
You are showing (based on your numbers from the scale) that the weight of the loaded truck, with and without the trailer, changes by 520 pounds. You naively (or intentionally) said "difference between the front and rear axle" is 260 pounds. With a w/d system, the difference could actually be 260 pounds on the front axle and 260 on the rear axle; but your numbers (without w/d) -- (if you weighed each axle separately) will undoubtedly show that ALL of this weight (if not more) is on the rear axle only. That can cause all of the problems above, and then some.

OK, now I've looked at the specs of your trailer. Your loaded tongue weight is high...you have not, however, exceeded the weight ratings for the truck (that I know of), as long as your "loaded" weights include most (or all) of the passengers you'll be traveling with.

I'm really trying hard to shorten the response here...

What my opinion would be:
Decrease your tongue weight. Be sure to travel with your tanks EMPTY. Get your tongue weight under 500 pounds (in fact, you can move some weight of "stuff" inside the trailer toward (but not behind) the trailer axle); move more "stuff" into the truck, if you have a true truck weight (INCLUDING passengers) under the GVWR of the truck.
I really like the idea of a w/d system (dual cam type) because the sway-controlling ability of this type of hitch is FAR superior to ANY friction-type sway control, and it is better in ALL conditions. So unless the manufacturer FORBIDS the use of a w/d system, I'd go with a dual-cam type W/D system with lighyt spring bars.

If you DO avoid a W/D system altogether, lighten your tongue weight.
But:
A. Don't go any lighter than the trailer's specs (430 lbs for a 16' CCD Bambi, 510 pounds for a 19' CCD, etc).
B. Don't go any lighter than 10% of the overall trailer loaded weight.
C. Don't go any heavier than what the truck's owners manual OR the hitch itself (printed on the hitch) says (and I didn't mention this above).
D. Check hitch ball height after hitching (should be 17.25-18", depending on trailer model, per A/S).

Whatever route you end up going, try setting it up and then do some test runs....on the highway, as well as evasive manuevers (quick stops, lane changes, etc) - before loading up the family. If you're not happy with the way it handles, don't settle for that setup.

[basecamp]

Go to any hitch manufacturer on the WEB and they should explain the concept. Your trailer has a hitch weight of over 400lbs so you should have over 400lbs extra weight on your TV. Make sure your trailer is balanced properly, if the weight on the hitch is too light you will have control problems, also, towing a single axle trailer has more tendency to sway than a multiple axle trailer. I'm sure you want to put equipment in your truck which will add hundreds of pounds to the rear axle of your TV. Balance your truck load using a WD hitch and balance the load in your trailer as well.

[Van]

Well, for what its worth, i tow without a WD hitch and have never had any problems. Trailer tows well and the few evasive maneuvers and quick stops i have had to make were uneventfull.

[Toasty's Dad]

Hello funchucky,

That 260 difference is based on weighing the axles separately. I weighed each axle separately first, with the trailer hitched up, then I separated the TV from the trailer and measured the loaded truck on one pan, the tongue on another pan, and the trailer axle on the rear pan.

So the numbers aren't speculation; but are they acceptable?

THANX,
jon

[funchucky1]

Jon,
So you're saying you weighed each truck axle separately with the trailer hitched, then you weighed each truck axle separately with the trailer unhitched.....and determined that there is an additional 260 pounds applied to EACH axle (front and rear) when hitching up?
This seems like a physical impossibility without a W/D system.

I read that the difference in truck weight between: A. hitched (5340 lbs) and B. unhitched (4820 lbs) is 520 pounds. Without a W/D setup, all of this 520 pounds would be on the rear axle (in fact, because the hitch is as far behind the rear axle as it is, your front axle load would probably DECREASE, and the rear load would increase by more than 520 pounds). That's physics.

This is obviously important...

But regardless, can you go check the trailer hitch - for a "tongue weight" limit? I fear it will say 500 pounds, as many 5000 pound-rated hitched do. This is a concern because no matter WHICH truck axle the weight is on, my math still shows 520 pounds on your hitch (with the trailer loaded as is).

Just my $0.02...

[bryanl]

Chuck had good advice but I strongly disagree with the suggestion to lighten tongue weight. You want 12% +/- of trailer weight on the tongue for proper handling. If your hitch or tow vehicle or hitch can't handle that weight, then get one that can.

The Reese Dual Cam is on a par with the Lindon Equal-i-zer but both depend upon the weight distribution loads to implement sway damping. A friction bar is not usually as effective but at least does not depend upon any weight distribution system. Sway should not be an issue unless you have a short wheelbase, long rear overhang, or some other problem.

As far as what is acceptable, criteria one is the owner's manual. It should tell you what kind of load is acceptable for dead ball weight and GCWR. It probably doesn't talk about axle weights (except for GAWR). Criteria two is your own experience with the load on the road.

And please watch out for this emergency fear mongering. That is too often used as a Bogeyman.

[funchucky1]

Actually, I wholeheartedly agree with Bryan in the tongue weight department. The more, the merrier, up to maybe 15% or so. 10% is the standard minumun rule of thumb, but 12-15% will provide a notably more stable towing experience. I just fear that >500 pounds on the hitch of a Ridgeline is too much. The hitch and owner's manual will hopefully answer that question.
-Chuck

[wkerfoot]

Originally Posted by Toasty's Dad

Hello funchucky,

That 260 difference is based on weighing the axles separately. I weighed each axle separately first, with the trailer hitched up, then I separated the TV from the trailer and measured the loaded truck on one pan, the tongue on another pan, and the trailer axle on the rear pan.

So the numbers aren't speculation; but are they acceptable?

THANX,
jon

Jon,

How far down does the rear bumper go when you hook up the trailer?

Bill

[Toasty's Dad]

hi chuck,

the max tongue wt is 600 lbs for my class-C, Honda-installed hitch, according to the owner's manual.

here are the ###'s with the trailer loaded and hitched to the loaded TV. for this test, i had the front truck axle on one pan, the rear truck axle on one pan, and the trailer axle on one pan:

Front Axle: 2540
Rear Axle: 2800
Trailer Axle: 2900
Gross Wt: 8040

So that's where I come up with a difference between the front/rear truck axles of 260 lbs.

then, i unhitched, measurd the weight of the entire truck on one pan, the trailer tongue on one pan, and the rear axle on a third pan:

Truck: 4820
Tongue: 540
Trailer Axle: 8060

hope this helps,
jon

[Toasty's Dad]

Hello Bill,

Can't easily hitch up right now to tell ya, but I'd say the ball sinks between 1 - 2 inches when the trailer tongue comes down on it, and there is no to little noticable dip in the combo to my eye. The trailer looks level hitched, again just to my eye.

THANX,
jon

[funchucky1]

Hey, Jon.
I'm assuming your last trailer axle weight was an error ...

Ultimately, you are:
Within "Towing capacity" for the truck
Within tongue weight limit for the truck
Within GVWR for the truck
Within GCWR (for truck & Trailer)
Within trailer axle rating (per Airstream)
Following mfr recommendations (NO W/D setup)

........so it sounds okay, technically.
Does the owner's manual provide a weight rating for each (front and rear) axle? As long as you are not exceeding a specific rear axle rating....I don't see a problem, technically (am I missing anything else?)

DO check your ball height when hitched...A/S says 18" for your trailer.

Drive it...and see how it feels...

-Chuck

[Toasty's Dad]

[quote=funchucky1]
>I'm assuming your last trailer axle weight was an error ...

DOH! Yup, the trailer axle weight was 2900 in both weighs. I hate it when I do that.

>Does the owner's manual provide a weight rating for each (front and rear) >axle? As long as you are not exceeding a specific rear axle rating....I don't see >a problem, technically (am I missing anything else?)

The limits are 3105 on the front axle and 3245 on the rear.
So should be OK there.

>DO check your ball height when hitched...A/S says 18" for your trailer.

I definitely will.

>Drive it...and see how it feels...

Seems OK with what we've done so far, but I think I'll also gonna try simulate some panic moves in a BIG EMTPY parking lot.

THANKS VERY MUCH, Chuck.
jon