WDH Question

If it helps, I use a Reese Pro WDH with 1200lb bars and my 2619 has a swing tongue. eTrailer has them on line along with a wide selection of others that I suspect will work as Bill says.....
I also use air bags to level the truck when i take my ATV along in the bed of the Tundra.

I'm not sure if I believe that leveling the truck does not put at least put most of the weight back on the front axle. Seems like it has to. It feels like it does when I drive it, and I use one less link on the WDH hitch when I use the 2 together. After leveling the truck with the air bags and ATV in the bed. There is only a small amount of sag when I put the TM on the WDH hitch. The tension on the bars is very light. Maybe I have too much air in the bags, but it seems silly to me to let air out just so I can relevel it with the WDH. I admit, I don't have a complete understanding how the 2 systems interact with each other.....so go easy on me.

[mecicon]

I agree, if we are lifting the weight off the rear axle of the TV by manipulating the angle the weight has to go somewhere.

The dealer that I bought the TM from was more inclined to air shocks than a WDH.

[Bill]

I agree, if we are lifting the weight off the rear axle of the TV ...

Well, that is the point. Air bags do not lift weight off the rear axle of the tow vehicle.

Try this thought-experiment. Lie on your back on the floor. Put a 10-pound bag of flour on your chest. Put a sturdy balloon between the bag and your chest. Inflate the balloon. Does any of the bag's weight shift toward your feet? I don't think so. It still comes down on your back.

Bill

[mecicon]

I understand your analogy; however I am not rigid like a TV and are we not placing the bag under the vehicle between the suspension not between the load and the TV?

I am not arguing, help me understand. This was the dealer's insight.

[ZekenSpider]

mecicon;

Try this thought experiment. Maybe it will help illustrate what happens when using a WDH.

Insert a 3 ft long bar into the TV hitch receiver (2"x2" hole).

Lift up on the other end of the bar as hard as you can.

There are now three things supporting the TV, the front axle, the rear axle and you. This procedure removed weight from the rear axle, put more weight on the front axle and of course put weight on you.

The amount of weight transferred to the three different support points is directly related to the distance the three points are apart from each other.

In this experiment, you represent the trailer tongue (the flexible nature of the tongue, hitch & ball is made essentially into a rigid bar by the WDH).

If you used a 15' long bar instead of a 3' long bar, you could lift more weight off the TV rear axle, add more weight to the front axle, and in this case you would represent the trailer axle.

I hope this helps the visualization process.

I'll try to make a copy of the famous WDH analysis that Ron Gratz created for another forum and attach it to this reply. If I'm not successful, I'll send it later after I make a .pdf out of it.

Jerry

[Mr. Adventure]

Originally Posted by mecicon

I agree, if we are lifting the weight off the rear axle of the TV by manipulating the angle the weight has to go somewhere.

The dealer that I bought the TM from was more inclined to air shocks than a WDH.

Your dealer is wrong. Air shocks and other spring helpers give you stiffer rear weight support, but do not shift any weight around or address the unloading of the front axle caused by the tongue weight on the hitch ball. Think of your Tow vehicle as a lever and the rear axle as the fulcrum between the hitch ball and the front wheels. The WDH is a spring loaded way to lift up on the trailer hitch point by pulling down on the trailer frame.

Unloading the front axle is dangerous because it reduces your ability to steer and brake when you're towing, when you need more of these, not less.

Brake controllers:
Tekonsha makes the Prodigy brake controller, but also makes other models. Do not use the cheaper models that increase braking by timing how long you've been applying the brakes. The smarter Prodigy gives you more brake boost right away, instead of taking it's darned sweet time when you're in a panic stop. Real Adventure: I had a cheap Tekonsha controller with a 29' travel trailer and a full sized Ford van. We were on a 45mph road in a light rain. The traffic light turned red ahead, and I slammed on the brakes. The antilock brakes kept the tow vehicle fully under control while the trailer shoved me right into the intersection, with the brake controller figuring "this can't be that big a deal, because the inertia for this stop doesn't seem all that hard (skidding in the rain), and this guy hasn't been on the brakes long enough to decide he's really into this." Cross traffic drivers, out of respect for an out of control RV, held short of the intersection until I got things sorted out. Lessons learned: 1) This is what the lever on the controller is there for, and 2) that brake controller is a problem.

[Wavery]

Originally Posted by mecicon

I understand your analogy; however I am not rigid like a TV and are we not placing the bag under the vehicle between the suspension not between the load and the TV?

I am not arguing, help me understand. This was the dealer's insight.

In order to rationalize the air shocks adding weight to the front, you must first ask yourself where that weight is coming from.

Adding air shocks does not change the gross weight of the truck (except for the slight difference in weight of the air shocks vs std shocks).

In order to add weight to the front, you must figure out how air shocks subtract weight from the rear. The answer is simple........there is no weight exchange at all. The only thing that happens its that you have added a (air) spacer between the axle and the frame that lifts the frame. Absolutely "0" weight shift.

Now, if you did the same thing to a tank of water, the water mass would shift to the front because the surface of the water will always be level. You would end up with more water weight in the front and less water weight in the rear. Your tow vehicle is not liquid so there is no shift in mass.

Now.....if your lift were very extreme........like over 45 degrees, there would be a weight shift because you have changed the leverage and fulcrum angle substantially. Adding air shocks would lift the rear 2 degrees or less. The weight shift wouldn't even be measurable.

I hope that helps.

Then I need to figure out the proper way to use the air bags and WDH at the same time to get the proper effect. As I said, when I level with the air bags, the WDH seems to do very little and is barely loaded.

Here's my analogy.......take a 200 lb beam, attach a pivot point 3/4's of the way back, (like your rear axle). Put your head under the front of the beam. I'll lift up on the rear of the beam. Tell me if you feel any pressure.

[mjlaupp]

Originally Posted by Redhawk

Then I need to figure out the proper way to use the air bags and WDH at the same time to get the proper effect....

1) Load the bed toys in the truck
2) Use the air bags to level the truck
3) Hook the trailer to the truck
4) Use the WDH to level the truck & trailer.

See page 5 of the instructions for an Eaz-Lift WDH:
http://www.eaz-lift.com/eazlift/Inst...structions.pdf

[mecicon]

Originally Posted by ZekenSpider

mecicon;

Try this thought experiment. Maybe it will help illustrate what happens when using a WDH.

Insert a 3 ft long bar into the TV hitch receiver (2"x2" hole).

Lift up on the other end of the bar as hard as you can.

There are now three things supporting the TV, the front axle, the rear axle and you. This procedure removed weight from the rear axle, put more weight on the front axle and of course put weight on you.

The amount of weight transferred to the three different support points is directly related to the distance the three points are apart from each other.

In this experiment, you represent the trailer tongue (the flexible nature of the tongue, hitch & ball is made essentially into a rigid bar by the WDH).

If you used a 15' long bar instead of a 3' long bar, you could lift more weight off the TV rear axle, add more weight to the front axle, and in this case you would represent the trailer axle.

I hope this helps the visualization process.

I'll try to make a copy of the famous WDH analysis that Ron Gratz created for another forum and attach it to this reply. If I'm not successful, I'll send it later after I make a .pdf out of it.

Jerry

This was very helpful. Thank you.