Safety- Do you know what your hitch is rated at

After doing much looking research, etc when I was thinking about a Weight Distribution Hitch I discovered something scary. The Hitch that came on my Ford F150 has 2 ratings. One without a WDH (500 lbs) and one with a WDH (a lot more). The tongue on my 3023 was 750 pounds! I needed the WDH for this reason alone. Forget all the weights on axles, measuring how high your front goes up, or the rear down. If your TM tongue weighs more than your hitch is rated, you need a WDH.
Just lay on your back and look up under the rear of the TV. There should be a label with all the ratings on the hitch. Here is a way to measure your tongue weight:
http://www.ehow.com/how_6293460_meas...ue-weight.html

There are other ways that may be a wee bit more accurate but this works and it is with materials we all can get our hands on.

Dave

Random thought...

You are towing across the middle of nowhere and your WD hitch fails. You can no longer use the bars to distribute the weight.

It is 100 miles to the nearest town.

It would be very tempting to just leave the bars off and tow as if it were a non WD hitch.

Questions:

1 can a WD hitch fail in this manor?

2. How much safety margin would make one comfortable enough to tow without the spring bars.

The alternative is to leave the trailer where it is and drive to someplace that can fix the WD hitch.

Or am I just dreaming up a failure situation that can never occur?

Just a random answer...

I towed from Ohio to Florida and back without a WDH and had no problems. Therefore if the WDH should fail in some manner I would continue to tow but at a reduced speed and with more caution knowing I was testing the quality of the bolts the additional weight is trying to shear off. I know I can do it for some time, I did it because of ignorance. Now I know better so will use my WDH so that I am as safe as possible.

Yes the engineers always leave a few pounds over the rating for safety and for folks who want to push to the edge. I am not one of them. If I am going to get killed, or kill someone else in a wreck I can only hope it was not because I did not follow the manufacturers recommendations.

Each of us gets to make those decisions all by ourselves.

[scrubjaysnest]

Another random answer....we got away with towing ours from TX to Fl without a WDH, about 1100 miles.

I've never understood these numbers.

My factory installed receiver is rated at 500/5000# (tongue/trailer) weight carrying and 1150/11500# weight distributing.

Why would the receiver be able to handle an extra 6500# of trailer with a WDH? I understand why the TRUCK can handle more, but the receiver itself?

And if you put on 1150# of tongue weight and ~level the truck with a WDH as per Ford's instructions, the amount of upward force on the receiver should be about the same, say ~1000#.

Why can the receiver's bolts/welds support 2x the upward force as the downward? I've looked at the receiver, and it sure doesn't look asymmetric in design (although I'm no Mechanical Engineer).

Again, I think it has more to do with what the truck as a whole can handle.

In my case, I've switched to a very short tow bar and ditched the WDH, even though my tongue weight is ~580#. If anything, the handling is better because I've reduced the distance from the ball to the truck's rear axle by about 7.5". I'm also putting less weight on the trailer's axle.

Other vehicles have higher receiver ratings. My old Tacoma's factory receiver was 650/6500# without a WDH. When I was looking at the VW Touareg, the specs were 770/7700#, and they said never to use a WDH.

I'm also suspicious because all these non-wdh receiver ratings are max trailer weight divided by ten.

I found this interesting: http://www.automobilemag.com/feature...t/viewall.html

The other article I read stated that Toyota has already implimented the new ratings, but Ford was dragging their feet and waiting on new models to be introduced. Not sure about anyone else.

[Mr. Adventure]

Without the WDH, the Hitch Receiver carries all the load on the rearmost bolts. With the WDH, it pulls down on the front bolts and pushes up the same amount at the rear (this is how the WDH does it's thing with weight on the axles). The effect at the reciever attach points is to spread the weight so that the hitch receiver can handle a higher tongue weight with a WDH than it can without one.

This is universally true of all WDH applications, but not all manufacturers bother to provide separate ratings with and without a WDH. I can think of 2 reasons for a manufacturer to prohibit a WDH: 1) if the hitch receiver that comes with the vehicle is not rated for a WDH (WDH bars could be strong enough to bend a non-WDH rated receiver), and 2) there is no good way in the case of some particular vehicle to provide adequate front hitch receiver mounts which are able to support the WDH loads.

To the PopBeavers question

Questions:

1 can a WD hitch fail in this manor?

2. How much safety margin would make one comfortable enough to tow without the spring bars.

The alternative is to leave the trailer where it is and drive to someplace that can fix the WD hitch.

Or am I just dreaming up a failure situation that can never occur?

An overloaded hitch can bend metal, and everything has failure points. Though I've never heard of a WDH failure, you could visualize that concept pretty easily just thinking about missing/loose/damaged nuts/bolts/fasteners which forced you to temporarily put the WDH away and tow with a standard ball mount. A WDH still works with just one of the 2 bars, but a bit less than half as well. The question is, how far can you bend the envelope before it breaks?

The smarter the manufacturers get about cutting things closer with their computers, the less slop they will allow for in their designs. Given that tongue weights are static loads and dynamic loads are always the design limits because they have the potential to be substantially higher than static loads, you can probably get by with a whole lot just by taking things easy (staying on smooth roads and going real slow over bumps, for example). In some situations, that could be harder than others. I'd guess you might get by with a 50-100% overload, but I'm just guessing and of course this is highly application dependent.

To the Brulaz questions

Why would the receiver be able to handle an extra 6500# of trailer with a WDH?

...

Why can the receiver's bolts/welds support 2x the upward force as the downward?

...
I'm also suspicious because all these non-wdh receiver ratings are max trailer weight divided by ten.

Re extra 6500# of trailer: You're right, it's really about how the truck can handle more if the load is better distributed. But the WDH not only distributes axle loads, it also distributes loads at the hitch receiver attach points.

Re bolts/welds support 2x the upward force as the downward: Without a WDH, the forward bolts don't have to do much besides handling upward forces on bumps. The rear bolts have to carry the tongue besides the downward bump forces.

Re max trailer weight divided by 10: You're right, they are taking shortcuts by making the assumption that 10% of the trailer weight gets put on the hitch ball when reality should support something more like 7-14%.


Redhawk: Thanks for sharing the link. This is the first time I've read carefully about the new standards.

Some observations:
- Most of the methodology is about durability and power, not stopping and safety.
- Brake fade is specifically excluded!
- The bar is substantially lower for heavier vehicles (2x stopping distance is going to be allowed for trailer ratings over versus under 3000#)!

fwiw,

My son is a mechanical engineer. He designs the structure for satellites. There is no opportunity to perform a repair after launch. Quality is critical and so is weight (mass). They cut it as close as they can (dare).

I am a software engineer. In the late 80's we were designing software to perform automatic mesh generation and stress analysis. We were the first company to figure out how to automatically create a mesh. If you are not an engineer then my use of the word mesh probably means noting to you. That is OK.

What we were doing in the late 80's required a multi million dollar mainframe computer to run. My son uses a high end PC running Windows to run those simulations.

When you make it easy to create a mesh automatically (minutes instead of days) and you have enough computer power to run the simulations (PC versus mainframe) then the design engineer can execute a tremendous quantity of tress analyses.

Therefore, it is my opinion that today's engineers have a lot less slop in there calculations than they did 10 years ago. Because they can now and could not back then.

Just one man's opinion.

And some of us actually used slide rules in a previous life ...

And I forgot to say, the bolts holding my receiver onto the frame are aligned vertically (perhaps a little off from vertical). Three very large bolts on each side bolt onto a heavy bracket welded to the frame. I'm not worried about the bolts giving way, or really any other part of the receiver. It's just massive; part of Ford's optional "Maximum Tow" package.