WDH with Swing-away Tongue

[Philip]

Hello,

I noticed that there has been virtually no discussion as to what forces the WDH puts on the TM frame between the chain connection and the ball cup.

I have a fair background in statics and as far as I can figure the bending moment between the chain connection and the ball cup on the TM frame is actually REDUCED if you use a WDH as opposed to not using a WDH. Just think about it this way - the WDH lifts the rear of the TV in order to shift some of the tongue weight forward onto the TV's front wheels. In order for this to happen the tongue weight on the ball must be reduced somewhat when the WDH is in operation. The bar of the WDH takes up this tongue weight. This reduces the bending moment on the TV frame between the TV ball cup and the chain connection point.

So, if your WDH chain connection point is aft of the TM swing hitch connection pins the load(bending moment) on the swing hitch is actually reduced with a WDH. Of course the bending moment on the TM frame aft of the chain connection point(and also on the TV frame) is INCREASED with a WDH. You increase the load on the TM tires with a WDH.

The key here is to make sure your WDH chain connection point is aft of your TM swing hitch pins. If it is not it will increase the bending moment on your swing hitch.

I hope this helps clear things up.

Take care,

Phil

You would be interested in the Ron Gratz analysis. See the attachment to this post:

http://www.trailmanorowners.com/foru...4&postcount=15

[Mr. Adventure]

I think the WDH adds bending load to the trailer frame either way.

Another important issue is the much better distribution of the loads on the bolts that attach the hitch receiver to the TV when you use a WDH. It's probably the reason that many manufacturers rate for higher tongue weights when you use a WDH vs without.

[Philip]

Hello Folks,

Thank you all for your comments on this complicated analysis.

I finally found a web site which has a complete analysis of the the forces on the TV & TM with a WDH. I was wrong in saying that the tongue load is reduced with a WDH. As shown on the following web site it actually stays the same.

Take a look at http://www.machineunderground.com/tr...how-works.html to get a complete understanding of the forces with a WDH. Sorry for the bad information.

Take care,

Phil

[Mr. Adventure]

Originally Posted by Philip

Hello Folks,

Thank you all for your comments on this complicated analysis.

I finally found a web site which has a complete analysis of the the forces on the TV & TM with a WDH. I was wrong in saying that the tongue load is reduced with a WDH. As shown on the following web site it actually stays the same.

Take a look at http://www.machineunderground.com/tr...how-works.html to get a complete understanding of the forces with a WDH. Sorry for the bad information.

Take care,

Phil

Phil, don't feel bad. I think your link reference is itself still short of a complete understanding. The example hugely overstates the weight distribution and capacity of the spring bars and hitches we use. 1000 pounds per bar would produce about 5 times the weight distribution I'm actually doing. 5 times the load on the bars would require bending the bars 5 times as far, which would be something like 20"! If there was a way to do that, it couldn't be a good idea.

While the actual tongue weight doesn't change, the effective tongue weight does, and of course that's the point of the WDH.

Those old textbooks have to be here in the attic somewhere...

Hi, I need help again

I have been reading some of this swing tongue stuff and I never realized that I might have a swing tongue. I DON’T HAVE A CLUE HOW IT WOULD WORK ANYWAY. I do use the WDH bars I have and they work great. I posted three pictures maybe I can be helped?

I really could use the extra two feet in the garage but I have been fine since May when we bought the TM from a trailer dealer. I just would like to know whay I have.

Any information would be wonderful.

I am STILL a Rookie on the TM but I am learning so much. We love our La-Z-Boy

Oh! How would I learn how to use it?

Dave

[ShrimpBurrito]

Others can comment on the swing tongue, but I noticed you have a screw-on chain link on your ball mount. Is that where you connect your break-away cable? If so, that's not a great place for it -- if the ball mount separates from your TV, the TM brakes will not activate. It's best to connect the cable to the TV frame, or absent a good spot for that, at least to the TV hitch where the safety chains connect.

Dave

Thanks for the tip I appreciate that....Still learning these things

Dave

[MudDog]

From the pictures, you DO have a swing tongue.

Here's what I do:

1) get the trailer in the spot you want it chalk the wheels/un-hitch.

2) raise the tongue and lower the front jacks to the same height

3) lower the tongue jack so now the trailer is resting on the front jacks instead of the tongue jack

4) See those brassy looking pins with the D shaped ring on top? On the bottom you can un-clip a smaller pin that keeps the large pin from lifting out. Once the pin clip on the end of the chain is removed from the large pin you should be able to pull the large pin out.

Now you should be able to swing the two feet in front of the pins around (the remaining pin on the other side will act like a hinge).

I've attached pictures showing the pin and my hitch swung around.

--jim

Originally Posted by MudDog

From the pictures, you DO have a swing tongue.

Here's what I do:

1) get the trailer in the spot you want it chalk the wheels/un-hitch.

2) raise the tongue and lower the front jacks to the same height

3) lower the tongue jack so now the trailer is resting on the front jacks instead of the tongue jack

4) See those brassy looking pins with the D shaped ring on top? On the botton you can un-clip a smaller pin that keeps the large pin from lifting out. Once the pin clip on the end of the chain is removed from the large pin you should be able to pull the large pin out.

Now you should be able to swing the two feet in front of the pins around (the remaining pin on the other side will act like a hinge).

I've attached pictures showing the pin and my hitch swung around.

--jim

Thank you so MUCH for this information it is great. I guess the front will rest on the front jacks all the time till our next trip??? I heard the jacks hold 5,000 lbs so I should not have to worry about that?

But that will give us so much room in front to play with and walk around.

Dave