Weight Dist. Hitch Question

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Billabong

Member
Joined
May 3, 2006
Posts
5
Hi all,

Been looking at travel trailers, and there's one concept I can't seem to wrap my brain around.
The tow vehicle is a Ford Expedition w/ factory tow package (2" receiver, 7 pin harness).
Rated for 5,000lbs, or 7,500lbs with weight distribution.
What I don't understand, is to be able to tow 7,500lbs, do I need a new receiver and hitch, or just the hitch?

If it's just the hitch (tongue & ball), with the same receiver, how does that "distribute" anything? Does the hitch attach to other points of the tow vehicle's frame?

I'm a little confused.

Thanks!
 

Tom

Administrator
Joined
Jan 13, 2005
Posts
48,937
I should let our towing experts answer, but I'm sure they'll correct any mis-statement .....

If you look at this photo of a WD setup, you'll see that there are a couple of spring bars attached to the part that slides into the receiver. (That part is different from one that merely has a ball attached). The other end of the springs are attached to the trailer frame with chains. The chains are used to increase the pressure on the springs and the springs push up on the rear of the tow vehicle, which effectively transfers some of the load to the front axle of the tow vehicle. Increase the tension on the bars and more load is transfered from the rear axle of the tow vehicle to the front.

This photo shows all the pieces of the setup.

Forum staffer Carl wrote an article for our library explaining how to adjust a WD setup. Click the Library button above, select Towing and towables, then click Using & adjusting a weight distributing hitch.
 

Lowell

Well-known member
Joined
Aug 15, 2005
Posts
2,221
Location
Tempe, AZ
It sounds like your Expedition with the tow package has the tow vehicle portion handled.  The weight distribution system will just slide into your receiver.  When we were looking for our trailer,we found that all the dealers we talked to included the price for the weight distribution equipment in the trailer price.  When you go to hook up a weight distribution hitch, you will find that it a takes a few more minutes and a bit more cranking of the trailer jack.  But your dealer will show you how to do it.  It isn't too difficult. The parts are a bit heavy but they break down so you can pick up and slide them in one piece at a time.
Jake
 

Carl L

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Mar 14, 2005
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west Los Angeles
If it's just the hitch (tongue & ball), with the same receiver, how does that "distribute" anything? Does the hitch attach to other points of the tow vehicle's frame?

Most weight distributing systems consist of special ball mount, a pair of steel spring bars that fit into sockets called gudgeons in the ball mount, chains attached to the ends of the spring bars, and a pair of chain lifts fastened on to the A-frame of the trailer.  Trunnions on the ball mount end of the spring bars transmit the force of the stressed bars to the ball mount and receiver to a twist that forces the front end of the tow vehicle down wards transferring load from the rear axle to the front axle.

Most system in addition to weight distribution, add an anti-sway subsystem.  Most use one or two friction bars to provide resistance to lateral movements of the trailer.  Reese has a dual cam system that uses cams on the end of the springbars to apply diffential force thru the bars to resist lateral movement.  All of these systems permit controlled lateral movement but quench uncontrolled sway at the start.  They really work and are a major contributor to the comfort and safety of trailer towing.    I am a particular fan of the Reese Dual Cam system, having used it for going on 15 years.
 

snowguy800

Member
Joined
Jun 14, 2006
Posts
20
This weight distributing hitch concept is definitely confusing for a newbie? :)

In our research of travel trailers it seems that there is a vast variability in the published hitch weights from the manufacturers.? We're looking at trailers with a gvwr range in the 6500#-8000# range to pull with our '05 F150 Supercrew (5.4L Trition with 3.73 gearing) and it seems like the hitch weights in the spec. sheets go anywhere from 450# up to 1000#!? I've seen that in your discussions you suggest that the hitch weight typically will fall in the 10%-15% range.? So, what does a person believe with regard to hitch weights?? Also, as I understand it, the weight distributing hitch spreads the hitch weight across both tow vehicle and trailer axles.. correct?

So, in our shopping should we ignore the spec sheets as it relates to hitch weight (since they seem to be so variable as to be unreliable) and know that we can adjust the weight distributing hitch system to level the load across all the axles?? It would seem that this would work as long as we keep the trailer gvwr within our towing capacity allowing for the 10%-20% cushion (depending upon geographic towing destinations) as you all suggest...

Thanks for all the great information you all provide!

David
 

Carl L

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Mar 14, 2005
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7,239
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west Los Angeles
I've seen that in your discussions you suggest that the hitch weight typically will fall in the 10%-15% range.  So, what does a person believe with regard to hitch weights?  Also, as I understand it, the weight distributing hitch spreads the hitch weight across both tow vehicle and trailer axles.. correct?

I did not say that the weight will fail with in the range.  I said the tongue weight range should fall in the 11-15% range with the lower end being the critical range.  A too light tongue weight can mean an unstable trailer.  Do the arithmetic.  If the ratio of the unladen, dry, weight is below the range specified, I would look for another trailer.

That said, the only weights you can trust are the weights you get from a scale.
 

Gary RV_Wizard

Site Team
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Feb 2, 2005
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At our Silver Springs FL home
As Carl says, the the loaded hitch weight must be near 15% of the total loaded weight to handle safely.  The numbers you are looking at in the brochures are the unladen (dry) hitch weight, which have little relationship to what it will actually be when loaded for travel.  But you know that your traveling weight will be quite a bit above the unladen (dry) trailer weight and might be as much as the entire trailer GVWR (the max loaded weight). Figure that your hitch (tongue) weight will end up as 15% of the GVWR and you can't go wrong. If you are absolutely sure your loaded weight will be significantlyunder the GVWR, figure it that way BUT make sure you weigh the rig before your first outing, to be sure you aren't kidding yourself..
 
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