please help! head is spinning. new to towing & the more I read the more unsure i am

[coralcrazed]

Originally Posted by brulaz

Would be good to see somebody check their axle weights before and after modifying their suspensions.

what in the world would that give you??? unless you wanted to see how much the air bags weigh. but you know, there is a better way to screw on the light bulb than holding the bulb and turning your body...

just weigh the air bag kit when you get them in the mail before you attach them to your vehicle.

Originally Posted by coralcrazed

what in the world would that give you???

Guess I wasn't clear. On other forums I've visited there are people who swear that suspension modifications like air-bags, air-shocks, extra leaf springs, and so on, make a WDH unnecessary. Whereas everybody here seems to disagree with that.

But I've never seen data proving it one way or another. Something like this:
Weigh the T.V. axles
Weigh the T.V. plus trailer
Calculate how much weight the trailer removes from the front axle and adds to the rear axle.
Now pump up those air bags or whatever, leveling the T.V.
Reweigh the T.V. plus trailer.
Any change in axle weights? We would expect very little change.

And, unless we're wrong, such info would be useful when trying to persuade others to use a wdh and not to rely solely on suspension modifications.

[coralcrazed]

Originally Posted by brulaz

Guess I wasn't clear. On other forums I've visited there are people who swear that suspension modifications like air-bags, air-shocks, extra leaf springs, and so on, make a WDH unnecessary. Whereas everybody here seems to disagree with that.

But I've never seen data proving it one way or another. Something like this:
Weigh the T.V. axles
Weigh the T.V. plus trailer
Calculate how much weight the trailer removes from the front axle and adds to the rear axle.
Now pump up those air bags or whatever, leveling the T.V.
Reweigh the T.V. plus trailer.
Any change in axle weights? We would expect very little change.

And, unless we're wrong, such info would be useful when trying to persuade others to use a wdh and not to rely solely on suspension modifications.

its simple physics... you can't remove weight once you have placed it in a vehicle, but you sure can transfer it to other axles. think of a see saw... remember when you were 5 and that 10 year old climed on the other end forcing you to hit the sky? welp, a one axle TM is the same way. now keep in mind that the position of the pivit point (wheel) is placed percisely in a location that allows for 10-15% toungue weight on the front. Problem with this is that we don't all drive the same cars or trucks. some have higher towing capacities (GCWR) than others. so what does all of this mean??? well back to the see saw in this case the TM and its exerting weight onto our cars bumper. lets say that weight is 500 lbs. if you put air pillows to raise that weight you are not taking it away... its still there and I would bet that the weight on the scale would be the same UNTIL the point that you pivot the weight so high that it shifts to the back bumper of the TM (that would mean that you would need to lift the toungue so high that it remains in the air (air bags cant do that). trailer axles are always placed further to the back of center always leaving some toungue weight which would always drive the front of the TM down on the front. remember that correct weighing of the toungue of the TM when hitched is when it is balanced perfectly horizontal. so air lifts or any lifting suspension that raises the toungue a few inches up will have little effect on the toungue weight. with all this said we are getting ahead of ourselves because remember that BOTH your TV and the TM need to be as horizontal as possible when towing. so think of it this way the lift bags only level the TV BEFOR hitching which in my case was important because I am loading it with gear and people causing the back axle to sink and front axle to rise making it hard to handle. by bringing the axle back to level (horizontal) with the aid of pillows in the TV the suspension is stiffer but the TV still has the same weight that you loaded into it. its just distributed better allowing better handling. You could achieve a level TV without air bags if you shift the gear and people further to the center of the TV percisely between the front and rear axle. But that would mean that all of my gear and my kids would need to be piled up on top of eachother and the stearing wheel would also need to be installed in the middle of the vehicle. since none of that is practical and we can't always shift the weight towards the front of the TV to level it... the next best thing is air pillows. same way a WDH does not take away the toungue weight of the TM. Its still there but essentially the WDH ****s the weight on the toungue to all of the axles connected. think of the toungue as a loose hinge that can go up down and side to side. now by adding the WDH you've kinda locked that hinge between the TV and the TM. The actual weight on the tongue would be difficult to measure once the WDH is connected as some of the weight transfered is from the TV to the TM and back to the TV during normal driving.

sooooo I don't think that there is any good substitution for a good WDH and one should always be used. however the use of a WDH does not always improve handling to the 9th degree. because you still have an existing suspension system in your TV which in my case is bouncy and needed stiffening for better handling, hence the air bags. Hope this helped clarify for you.

[Mr. Adventure]

"Any change in axle weights?"

Answer: None that's measurable on a truck scale.

Gravity works in a vertical line. Lifted higher, Sagging lower, holding firmer, with springs, without springs, rolling, stopped, or on jackstands, the weight at an axle doesn't change unless you significantly change the angle of the vehicle to the weight applied by gravity.

Extreme changes would move significant amounts of vehicle forward or aft of the vertical line of gravitational force. For a pathological example, if you put 60 foot wheels on the rear axle neither the trailer axle nor the front axle would be able to touch the ground at all, and the whole works would be carried on just the rear axle.

But we're talking about modest suspension changes involving a few inches up or down at the rear axle, producing negligible changes which I don't think you could ever measure on a truck scale. OK, getting geeky here, for a 5000# vehicle with a 110" wheelbase being lifted by suspension components from 3" down and moved up to level, I projected a less than 2 pound decrease in rear axle weight, with the same increase added to the front. If the suspension lift started below level and ended above level by the same distance, the effect would be exactly zero. You don't have to install suspension components to measure this because you'd get pretty close to the same effect with blocks under the tires, or bigger wheels as in the example above.

Maybe those other boards don't have enough engineers (we have a lot here, some would say too many).

Originally Posted by coralcrazed

<snip>

sooooo I don't think that there is any good substitution for a good WDH and one should always be used. however the use of a WDH does not always improve handling to the 9th degree. because you still have an existing suspension system in your TV which in my case is bouncy and needed stiffening for better handling, hence the air bags. Hope this helped clarify for you.

If I understand you correctly, then I disagree.

My TM weighs 3380 on the axle. If I were to shift 120 pounds to the TM axle I wold then be at the limit. iI see no value in doing that.

On the other hand, I tow with a large vehicle, presently my GMC 2500HD and previously with my Chevy 1500HD.

Before we bought the off-road toys, hitching the TM to the Chevy resulted in the rear bumper of the truck dropping 5/8 inch. I did not measure the rise in the front, but I certainly would not have been very much.

In a conversation with the factory in 2006 they advised me that I would not need a WDH.

If your statement "I don't think that there is any good substitution for a good WDH and one should always be used" was directed at small tow vehicles and not trucks then I would agree with you. I believe that adding a WDH to my configuration would cause problems instead of improving the situation.

[coralcrazed]

Originally Posted by PopBeavers

If your statement "I don't think that there is any good substitution for a good WDH and one should always be used" was directed at small tow vehicles and not trucks then I would agree with you. I believe that adding a WDH to my configuration would cause problems instead of improving the situation.

yes thats what I meant... smaller vehicles OR even some larger ones where the manufacturer used softer suspension springs to make the larger vehicle "feel" more like a transport vehicle, hence a softer ride rather than a stifer bouncier ride. If you look back to one of my posts here I even stated this.

The argument is not about the WDH but rather the validity of air bags in some situations. namely mine having said this I'm not sure I agree that a WDH would hurt you in your situation. perhaps you can explain how/why??? I agree there may not be much benefit to it if your TV is oversized for the towing job but to say that a WDH would cause problems??? I don't see how it would. It would add further weight distribution to other axles and I can't for the life of me come up with a reason how that could in any way be bad even if your rear axle can handle alot more and your TV is overkill for the job.

Originally Posted by Mr. Adventure

Maybe those other boards don't have enough engineers

Probably. Certainly explanations based on physical principles don't seem to "carry much weight". That's why I was hoping for some empirical data on weight distribution (or lack of it) with air systems alone.

But it's likely a waste of my time. They'd could always counter that the air suspension alone "feels ok, so I'm not going to worry about it".

[Mr. Adventure]

Originally Posted by brulaz

Probably. Certainly explanations based on physical principles don't seem to "carry much weight". That's why I was hoping for some empirical data on weight distribution (or lack of it) with air systems alone.

But it's likely a waste of my time. They'd could always counter that the air suspension alone "feels ok, so I'm not going to worry about it".

You're right, it is probably a waste of time, particularly since we're talking about a fair amount of effort to measure something that will turn out to be invisible, and measuring invisible things can be hard to do. I know of a person who believes the Earth is flat, and she presumably maintains her own personal engineering principles to support her ideas too.

A better question for air bag believers/WDH doubters would be how much does the front end rise when you hitch, and if the front is rising how does that fit into the lift-spring theory of weight distribution? What they are actually accomplishing is lifting the rear which masks lifting the front and thinking that they are coming out even. As always, the scale numbers will tell what's happened to axle weights.

Actually, "feeling ok" is important. But an unloaded front end becomes a false sense of security in a panic stop, so the answer would be to drive slow enough that the panic stop still fits into the space in front of you. A small number of mph would make up for 5% reduced braking (maybe putting the generator, extra battery, spare tire, and the kitchen sink on a front end carrier would, too). But I wouldn't tow at 70mph on the highways I'm most familiar with no matter what TV I had, simply because I know there are probably variables I haven't thought about that are still out there somewhere (Experience is something you think you have until you get more of it).

Originally Posted by coralcrazed

yes thats what I meant... smaller vehicles OR even some larger ones where the manufacturer used softer suspension springs to make the larger vehicle "feel" more like a transport vehicle, hence a softer ride rather than a stifer bouncier ride. If you look back to one of my posts here I even stated this.

The argument is not about the WDH but rather the validity of air bags in some situations. namely mine having said this I'm not sure I agree that a WDH would hurt you in your situation. perhaps you can explain how/why??? I agree there may not be much benefit to it if your TV is oversized for the towing job but to say that a WDH would cause problems??? I don't see how it would. It would add further weight distribution to other axles and I can't for the life of me come up with a reason how that could in any way be bad even if your rear axle can handle alot more and your TV is overkill for the job.

If I use a WDH to transfer more than 120 pounds to the TM axle then I will exceed the limit. What would I gane by transferring say 50 pounds from the hitch back to the TM axle? How do I set up a WDH so that weight is transferred to the front axle of my truck, but none is transferred to the TM axle. I see no way for that to happen.

I tow heavy. 4,100 pounds for the TM. 6350 pounds for the truck when empty. With cargo my truck probably weighs around 7500 pounds. 700 pounds just for the ATV.

[Bill]

Coralcrazed -

You probably don't want to re-open this topic. Last time we did it, things got pretty heated. As has been pointed out, actually weighing a rig (twice) would get the answer, but it hasn't happened. I recall suggesting a very simple experiment, involving a plank, a bathroom scale, and a couple cement blocks, that would also get the answer with a lot less work. But no one has reported actually doing it.

Bill