weight distribution system

[JimGolden]

You beat me to it Larry But, you saw it for real...I've only seen pictures.

I thought a guy did a similar thing (though didn't tow it that far) with a Chevy Citation back in the late 80's.

Crank in enough distribution and you can pick the back of the car off the ground.

I've not posted to this thread because I figured, it would go down hill really fast. Glad to see it didn't get too ugly

There are many variables involved to all of this.

The original poster did kind of make a valid point: If you have a heavy truck, you don't really need weight distribution. Especially if you have a diesel that has double the weight on the front axle already. Just look at the math. That does not mean you don't need anti-sway.

Let's say you have an F-350 gasser that weighs 7000lbs, and I have one with a diesel that weighs 8000. Let's say your front axle weight is 3500lbs, and mine is 4500lbs, all else being equal, and no trailer hooked up. The exta weight of mine is all from Rudolf Diesel's finest and the associated beef-up up front to mount. Let's say they are both crew cab long beds, and have a 170 inch wheel base. Let's also say that whatever WD hitch we are using has the ball 40" aft of the center of the rear axle.

OK, it is a simple statics problem. Pick a tongue weight....say it's 1200lbs. OK, with 1200lbs on the ball, and perfect weight distribution, you put 600lbs on the front axle and 600lbs on the back (you'd really have to crank on her to actually do that) and squat it down just right (assuming equal spring rates, etc. which they aren't but this is an example). So now you have 4100lbs on the front axle. On my truck, I have zero weight distribution. So I'm just dumping 1200lbs on the ball. Do the moment calc and I've added 1482lbs to the rear axle (you get leverage from the overhang) and I've removed 282lbs from the front axle. So I now have 4218lbs on the front axle. Even with no weight distribution, I still have 118lbs more weight on the steering axle than the gasser. So the details do matter. And the best way, like the others have said, is to weigh the thing.

Of course, if I had something like a half ton Suburban with a 5.3, it will have a relatively light front axle load, softer springs all around, and more overhang (typically) from the center of the rear axle to the hitch ball. So say it has a 120" wheelbase, a 50" overhang, and a very light front. You would need to use heavier load bars on that setup.

Unfortunately, it's not a one-size-fits-all situation. So you have to look at the trailer, look at the tow vehicle, look at the geometry of them, and go from there. Both my dad and grand dad have had multiple sets of load bars, at different ratings, for pulling the same trailer but with different vehicles. I know Reese And Eq are happy to sell you some

Weight Distribution and Anti-Sway are two separate entities. But, if you can kill two birds with one stone, then why not? That's why they've said for years the bigger and heavier the tow vehicle, the lighter load bars you want to use. With a big one ton diesel dually, you really don't "need" any weight distribution at all. If anything, you'd want one of those cushion hitches that help absorb the shock because it'd take the Rock of Gibraltar to move the springs on one of those. But, you always want to have the anti-sway for safety. With a Reese Dual Cam on a big dually, you'd probably want 600lb bars, as you're not going to lighten the front axle enough to matter, and you're certainly not going to settle the back of the truck with a little ol' silver trailer (maybe a 40' fifth wheel....). So you don't need 1200lb bars. Use the 600's, so that they flex enough to work as designed and give you the "Straight Line" or "Anti Sway" action without tearing the tongue off the trailer. Same thing for an Equal-I-Zer. Both of these hitches require a certain amount of deflection to work properly. If you used the heavy bars with the heavy truck, you're basically just dumping a bunch of excess load into the trailer tongue.

Another facet of this whole argument is Center of Gravity, which is probably more important than any kind of WD hitch. If the CG is too far aft, nothing will make it track right. A travel trailer's CG should be 10-15% ahead of the center line of the axle group. So if you have a single axle, measure the length of the trailer, multiply by .125, and measure forward from the center of the axle. That's where it should balance. Same with a triple and do it off the center axle. With a tandem, it'll be measured from halfway between the front and rear axle. The diddy about 10-15% of the trailer's weight as tongue weight is just a simplification of the real method, which is based on CG. Trailers are much like aircraft in that if you get them nose heavy, they are stable. Get them tail heavy, and they are unstable. Unstable = bad. A good hitch might mask it, but it's better to be loaded properly and have a good hitch setup. So put your blacksmith tools in the front. I once saw a utility trailer with a bobcat on the back that was loaded toward the rear. As I was passing him, I noticed his trailer start to fishtail. I accelerated quickly. It went from mild to wild in about 2-3 seconds and the trailer turned about 160 degrees, came up beside the pickup so they were going down the road like a capital V right behind me, and then the trailer flipped up over the pickup and rolled him off the right side of the road, completely over the guard rail. Guy was wearing his seatbelt, and so fortunately walked away from it as he slid through the bushes and didn't hit a pole or anything. But that is a classic example of an aft-CG unstable loading condition.

So to summarize this book:
Evaluate the tow vehicle and the trailer.
Don't go cheap on a hitch...spend the bucks and get a good one.
Determine the right load bars for the hitch.
Set it up right. If you need help, just ask on here. I've set up Reese's and Eq's, and others have too, as well as other brands. We're happy to help.
Make sure you have good tires, brakes, and lights that all work.

Go have fun!

[SteveSueMac]

Originally Posted by J. Morgan

Fwiw, while posting on a different WD thread I was compelled to go find the weight ticket I got last year while leaving town on my first trip out.

No WD

Steer axle 2,880
Drive axle 2,880
Trailer axles 6100
Total weight 11,860

I didn't remember that the steer and drive were exactly the same, but they were.

Interesting. Mine is not symmetrical without WD.

Just wondering - is symmetry on TV axles a goal or is that coincidental? My understanding is that the goal is to restore a required % lifted off the TV steer axle regardless of balance front/rear.

Mine starts at 4660 on steer and 3320 on drive. Add the trailer (no WD) and I'm at 4140 and 4900. With WD applied I'm at 4440 and 4500 (which I took to be coincidentally balanced). And note: my truck's manual wants 50% FALR (or 260# from the 520# lifted off the steer - the 4440 is 60# above the 50% FALR so I could back off the WD to balance that 60# difference - just don't know if that symmetry is a goal).

What do you all think?

[J. Morgan]

I don't think dead symmetry is important. I would say yours is close enough.

The fact that mine came out dead even is just pure chance.

Unfortunately I have never weighed my truck unhooked..... And I own a truck scale.....

By the way,,, I agree that anti sway IS a good idea, and good enough of an idea that I spent $1,246 on a Hensley last night.

I figure with the Hensley I can feel comfortable letting my wife drive.

[SteveSueMac]

Originally Posted by J. Morgan

I don't think dead symmetry is important. I would say yours is close enough.

The fact that mine came out dead even is just pure chance.

Unfortunately I have never weighed my truck unhooked..... And I own a truck scale.....

By the way,,, I agree that anti sway IS a good idea, and good enough of an idea that I spent $1,246 on a Hensley last night.

I figure with the Hensley I can feel comfortable letting my wife drive.

Thanks. Not related to hitches, but one of the most important "anti-sway" devices is practice and experience. Having purchased both the truck and trailer new and this being the first ever RV for us, DW and I felt it was a worthwhile investment to spend a weekend (the first after we bought the trailer) at the local CDL driving school for a Safe RV Driver course. She did WAY better than I did. The instructor INTENTIONALLY did everything REALLY slow. At first I was annoyed but he'd keep saying - hey, relax, it's CAMPING. :-)

Take it slow, GOAL (get out and look), relax, it's camping....all valuable lessons together with the technical aspects of backing it in to tight spaces, road tests in some hairy areas (highway is too easy ;-) ) and evasive maneuvers. Highly recommended no matter what hitch you buy.

Enjoy the Hensley. We have the ProPride (same principle) and just love it - admittedly with no other experience to measure against :-)

[J. Morgan]

I have had my CDL for over 25 years now, driven lots of miles and I still get out and look, LOTS, and I don't care who mocks me for it...

Truly excellent advise about the driving school.

By the way,,, not that it has anything to do with this thread,,,,, but my wife just walked in from a trip to Florida....

Do I tell her that I bought the hitch tonight or tomorrow....

[russellsue]

Man,
All these responces, great, but very confussing with drag factors, axle weight,symmetry, lot of math. I'm at the point where it would be easier to rent a hotel room and take a cab.I'm just going to do what I feel confortable with. I have never worried about what might happen, I live in the now and I also beleive there is no problem until there is a problem. 20 years a cop does that to you,you take day by day I do appreciate all the imput, I have learned alot.
Russ

[dznf0g]

Originally Posted by J. Morgan

I have had my CDL for over 25 years now, driven lots of miles and I still get out and look, LOTS, and I don't care who mocks me for it...

Truly excellent advise about the driving school.

By the way,,, not that it has anything to do with this thread,,,,, but my wife just walked in from a trip to Florida....

Do I tell her that I bought the hitch tonight or tomorrow....

Is she tired and cranky, or refreshed and perky?

1st case: tomorrow 2nd: now.

[J. Morgan]

She was tired, a little cranky, but glad to be home ...

I told her last night....

I explained that I had to place a bid on the lightly used hitch for half price,,, and it surprised me that I won it...... But at least now she can pull her trailer wherever she wants....

So far so good.

[J. Morgan]

Russ,,,

I am about the same way. Try it, see what works, if it works good, if it doesn't, fix it.

First time out after my first trailer rebuild I found I built the back of my trailer too heavy....

After returning from my first trip I remodeled my just remodeled rear bath.... fixed it and learned a few things,,,, pendulum effect on a vertical axis,,,, and lightweight construction techniques.

[dkottum]

Russell, it's not that complicated for your light truck and trailer. The heavy combo's cannot benefit from weight distribution the way you can.

So keep it simple, medium-sized w.d. bars to evenly distribute the added weight of the trailer on your truck's front and rear axles. You already use a sway control bar, that's good.

The hitch head and bars should be installed so they are tilted down toward the rear to assist with w.d. and give a better handling rig. When the w.d is applied, your wheel well measurements should show an equal drop front and rear (never lift the rear higher than equal or you will begin to lose rear wheel traction), and the trailer level.

Trailer and truck balance is mentioned. Just load your trailer so the front and rear of the trailer get about the same weight, concentrate heavy items over the axles. Load the truck with the heavy items as far forward in the bed as you can, keep the area behind the rear wheels as light as you can.

It will become second nature after you have used it a few times.

[Ron Gratz]

Originally Posted by JimGolden

---A travel trailer's CG should be 10-15% ahead of the center line of the axle group. So if you have a single axle, measure the length of the trailer, multiply by .125, and measure forward from the center of the axle.---

Instead of, "measure the length of the trailer", did you mean to say, "measure the distance from the ball coupler to the center of the axle"?

Tongue weight is equal to trailer weight TIMES distance from CG to axle(s) center DIVIDED BY distance from ball coupler to axle(s) center.

Tongue weight ratio is equal to distance from CG to axle(s) center DIVIDED BY distance from coupler to axle(s) center.

The 10-15% rule of thumb pertains to tongue weight ratio.

Ron

[JimGolden]

Ron,

I'd actually meant the length of the trailer. But, you also factor in the length you mentioned.

Say you have a 30 ft tandem axle trailer.
The center between the two axles is located 18' from the ball.
Say it weighs 10,000lbs loaded and ready to go.

Where do you want the CG? It should be 10-15% of the length of the trailer ahead of the centerline of the axles. So 10 to 15% of 30' would be 3' to 4.5' ahead of the CL between the axles.

So, we want the CG to be located at 18' - 3' = 15' behind the ball as the rear most limit, and 18' - 4.5' = 13.5' behind the ball as a happy forward limit.

Do the moment calculation from the CL on it and get something like:
10,000lbs * 3 ft = tongue weight * 18 ft ==> tongue weight = 1667 lbs.

10,000lbs * 4.5 ft = tongue weight * 18 ft ==> tongue weight = 2500 lbs.

Both of these seem a bit heavy, and my geometry here is probably slightly off from a real trailer.

But if we use only the wheel CL to ball length like you'd mentioned, that would make the weights go down. The CG lengths would shorten. It's be 10% to 15% of 18', which would be 1.8' to 2.7' instead of 3' and 4.5'. So the weights would go down to 1000lbs and 1500lbs. That does sound more realistic.

I'll have to think on this a bit. I have always used the length of the trailer for this calculation I'm not sure that you can neglect the tail overhang, because the weight back there is aft of the CG and certainly plays into (de)stability.

Bottom line is load it nose heavy

[AWCHIEF]

Originally Posted by m.hony

so-
How 'bout weight distribution on that new 23' trailer and Jeep Grand Cherokee?
I don't know if we are necessarily trying to achieve 50/50 weight distribution, but be within factory spec the same amount on the front and rear...
You see, a Yugo could tow a 34' Airstream if he knows something about science- using the levels of gravitivity and polarity-

It came with a Draw tite 600. The hitch bar is too short causing the trailer to ride a bit nose high. Really rides crappy with zero sway control. The trucks and high winds are blowing me all over the road. Hard enough keeping it out of the ditch on these crappy mid west roads. Worse that i have driven on in a long time. Nothing I can do about the hitch until I get home. Easy fix. I will be ordering a new Andersen weight distribution system as soon as I get home.

[AWCHIEF]

Change of plans. Looks like I will be going to the Blue Ox. The local Airstream dealership has one with the correct bars at a reasonable price. I think it will make a better WD/anti-sway hitch for my combination.

[dkottum]

Michael, seems like there are more people using the Blue Ox and like it. Please report how it works for your new combo. Congratulations on the new Airstream!

[J. Morgan]

Ok, I got the Hensley mounted and tested on a fifteen mile round trip to the scale at the Loves.

There are a lot of testimonials for these Hensley hitches and their ProPride brethren. My conclusion at this point is that the praise is deserved.

It makes the whole feel of my combination feel a lot better all around. Very similar to how a fifth wheel tows, super stable.

I read up on sway control a lot when I first started pulling my trailer, and I had decided to tough it out for a few trips while trying to find a Hensley or ProPride used at a price I could afford, not wanting to buy a lesser product.

I am glad I waited for the deal that felt right to me, and I am glad I didn't settle for less.

I paid $1246 for this lightly used Hensley delivered. After taking a test drive, I would pay full price for a new one if I had to.

[J. Morgan]

I had gotten a weight ticket a year ago no WD,

Steer. 2840
Drive 2840
Trailer 6100
Total. 11860

Today w/ Hensley

Steer. 3120
Drive. 2520
Trailer 6580
Total. 12220

The trailer Isn't exactly the same as it was then, but it should be close enough for comparison.

[SteveSueMac]

J. Morgan - what a gorgeous trailer!! You now have to pain that Hensley head to match your awesome trailer stripes!

Glad you're happy with it! Safe travels!

[J. Morgan]

Thank you!!!

Really it is a beat up old Sovereign with shinny clothes...

I do like the old girl though.

I think you are right about painting the Hensley. Maybe this winter.

[JimGolden]

I'll echo what SteveSueMac said. I really like your red accents! Sharp looking trailer!

I really would like to get one of those projection hitches. My Equal-I-Zer has done fine the past 7-8 years, but just by design the Hensley and the Propride are better. Good for you man! Many happy miles of sway free towing to you!

See ya on the road,