Bouncing in the air

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camperman1

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Since we have so many amazing interstate roads in this country that I have gone airborne on in my truck towing my travel trailer. Would gas charged shocks help with keeping the front from bouncing so much when going over a big dip in the road? You never know when you are going to hit one and they definitely make you hold the steering wheel tight.:oops:
 
I really do not think so. After my trip up to Wisconsin's Door County and Duluth and the Minnesota north shore, and back, I encountered a lot of really bad interstates. I think I-840 on the west side of Nashville was the worst. Each end of the bridges were terrible, as you say, launching you almost airborne.

My truck has Rancho 9000 adjustable shocks set to about mid setting, the trailer has shocks, nothing seems to help.

I've been on the Airstream AirForum (an RVLife forum) and specifically the hitch and tow vehicle forums. They discuss the Gen Y cushioned hitch, the Shocker hitch, and the Air Safe hitch, all of which you can connect a weight distributing hitch to.

Lots of praise for the Air Safe, with many long time users, the disadvantage being the weight. but I am seriously considering it.

Charles
 
Good morning camperman:

Have you weighed the combination loaded for a trip? After getting all weights you can get from a scale, have you done a proper evaluation of the numbers compared to all of your max weight ratings? If not, that would be the place to start. I might bet that you're overloaded and terribly out of balance. And no shocks in the world will correct that. Only you can correct that.

Remember, when you connect a trailer on a receiver hitch, you put considerably more weight on the rear axle than the honest tongue weight. For example: You could put a tongue weight of 1,000 lbs on the ball and actually increase your rear axle weight by 1,200 lbs. Some weight must be transferred from your front axle to your rear axle to achieve a balanced condition. My WAG is you're overloaded on your rear axle. And it's likely that your trailer is too heavy for your tow vehicle.

You will need to fill up with gas and weigh the combination to get steering axle, rear axle, trailer axle, and gross combination weight. Then drop the trailer in the lot and weigh the tow vehicle to get steering axle, rear axle, and tow vehicle gross weight without the trailer. Be sure to weigh the tow vehicle loaded exactly as it was loaded when you weighed the combination. And that includes driver and all passengers. I am assuming you only have one trailer axle. If you have two trailer axles, you will need to split them on different pads on the scale and weigh again to get individual axle weights. With two axles, you will have to weigh three times to get everything you need.

I will be happy to help you with weights and balance if you like. If you've never weighed before, contact me and I'll help you on weighing. If you do this and send me all the weights from the scale slips, plus all of your max weight ratings, I'll be happy to help you determine if you're loaded safely going down the road.

From what you described above, I don't think you're safe now. What would you do in a panic stop situation with this bouncing going on?

Dave
 
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If you have two trailer axles, you will need to split them on different pads on the scale and weigh again to get individual axle weights. With two axles, you will have to weigh three times to get everything you need.




Dave
What???
 
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Good morning Onyrlef:

On trailers that do not have weight distributing suspensions, it is easy to have one trailer axle carrying more weight than the other axle. This results in the tires on one axle having better friction between the tires and the road. The lighter axle will have less friction. Therefore, the wheels on the lighter axle may lock up in a panic stop sooner than the wheels on the heavy axle. And with the trailer brake gain set, the heavy axle can't use the extra traction. What this means is, you won't have optimum braking authority from the trailer wheels in a panic stop situation.

This is why you want the trailer really close to level, to evenly distribute the weight on all trailer axles, whether there are two or three axles. It is very common for TTs not to have weight distributing suspensions.

In order to get the weight values on each trailer axle, we need to isolate each axle on a scale pad by itself and take another weigh. If you have only two trailer axles, you can "split" them by putting the front axle on scale pad #2 leaving the rear axle on scale pad #3 by itself. This way, you can get an accurate weight for both axles in one re-weigh.

If both axles weigh the same, or very close there to, you will have better braking authority from all trailer wheels. An added benefit will be more even tread wear.

My reference to weighing three times is just this. I always weigh the combination first since that's how we pull into the truck stop. For the second weigh, you would pull just far enough forwards to put trailer axle 2 just barely, but fully, on scale pad #2. This will leave the rear trailer axle on scale pad #3 by itself. Then when you take a second weigh, you will have accurate weight figures for each of two trailer axles. This assumes your tow vehicle rear axle that was on pad #2 has move forward enough to where it is off of pad #2 and only the front trailer axle is on pad #2 now.

The third weigh is the tow vehicle only, without the trailer. This should be weighed with the exact load as it was loaded when you pulled onto the scale to weigh the combination, including driver and all passengers. Weighing the tow vehicle exactly as it was loaded when the combination vehicle was weighed is very, very important. If it is not the same, some of the weights that must be calculated, such as hitch, or tongue weight, will not be valid.

I always fill up on diesel, exhaust fluid, fresh water, and generator gas. I have a 5th wheel toy hauler with a full tank of gas for the toys as well. Since I have three trailer axles, I have one more step to way two trailer axles separately. So that gives me four weighs. I take all four weighs within about 45 minutes or less. Then go inside to get all four of my scale slips.

After weighing my trailer axles, I pull off the scale to park. I drop my trailer in the parking space while I drive my tow vehicle only back onto the scale to weigh it.

I hope I've answered your question. If not, please let me know and I'll try again. This is something we all need to fully understand so we can know that our vehicles are safe to drive. lol.

Dave
 
Howdy tymgcamp:

I didn't mention a WDH since that was not relevant to answering the question. But since you mentioned it, of course, a WDH will aid in the effort to level the combination vehicle.

But there can be some serious problems that cause some folks to think that using a WDH to level the rig will solve may be a dangerous proposition. If the reason the tow vehicle is squatting is because the tongue weight is too much for the tow vehicle to handle in any configuration.

Of course, there are tow vehicles that can handle the weight and a WDH may help transfer some weight back onto the front axle and in the process, work towards leveling the trailer which would be a good thing, better braking authority for one.

But to just think of putting a WDH on a tow vehicle because someone says that's what they would do without reviewing the weight and balance of the current combination is just irresponsible.

Dave
 
Good morning Onyrlef:

On trailers that do not have weight distributing suspensions, it is easy to have one trailer axle carrying more weight than the other axle. This results in the tires on one axle having better friction between the tires and the road. The lighter axle will have less friction. Therefore, the wheels on the lighter axle may lock up in a panic stop sooner than the wheels on the heavy axle. And with the trailer brake gain set, the heavy axle can't use the extra traction. What this means is, you won't have optimum braking authority from the trailer wheels in a panic stop situation.

This is why you want the trailer really close to level, to evenly distribute the weight on all trailer axles, whether there are two or three axles. It is very common for TTs not to have weight distributing suspensions.

In order to get the weight values on each trailer axle, we need to isolate each axle on a scale pad by itself and take another weigh. If you have only two trailer axles, you can "split" them by putting the front axle on scale pad #2 leaving the rear axle on scale pad #3 by itself. This way, you can get an accurate weight for both axles in one re-weigh.

If both axles weigh the same, or very close there to, you will have better braking authority from all trailer wheels. An added benefit will be more even tread wear.

My reference to weighing three times is just this. I always weigh the combination first since that's how we pull into the truck stop. For the second weigh, you would pull just far enough forwards to put trailer axle 2 just barely, but fully, on scale pad #2. This will leave the rear trailer axle on scale pad #3 by itself. Then when you take a second weigh, you will have accurate weight figures for each of two trailer axles. This assumes your tow vehicle rear axle that was on pad #2 has move forward enough to where it is off of pad #2 and only the front trailer axle is on pad #2 now.

The third weigh is the tow vehicle only, without the trailer. This should be weighed with the exact load as it was loaded when you pulled onto the scale to weigh the combination, including driver and all passengers. Weighing the tow vehicle exactly as it was loaded when the combination vehicle was weighed is very, very important. If it is not the same, some of the weights that must be calculated, such as hitch, or tongue weight, will not be valid.

I always fill up on diesel, exhaust fluid, fresh water, and generator gas. I have a 5th wheel toy hauler with a full tank of gas for the toys as well. Since I have three trailer axles, I have one more step to way two trailer axles separately. So that gives me four weighs. I take all four weighs within about 45 minutes or less. Then go inside to get all four of my scale slips.

After weighing my trailer axles, I pull off the scale to park. I drop my trailer in the parking space while I drive my tow vehicle only back onto the scale to weigh it.

I hope I've answered your question. If not, please let me know and I'll try again. This is something we all need to fully understand so we can know that our vehicles are safe to drive. lol.

Dave
No thanks, I believe that will do me.
 
Howdy tymgcamp:

I didn't mention a WDH since that was not relevant to answering the question. But since you mentioned it, of course, a WDH will aid in the effort to level the combination vehicle.

But there can be some serious problems that cause some folks to think that using a WDH to level the rig will solve may be a dangerous proposition. If the reason the tow vehicle is squatting is because the tongue weight is too much for the tow vehicle to handle in any configuration.

Of course, there are tow vehicles that can handle the weight and a WDH may help transfer some weight back onto the front axle and in the process, work towards leveling the trailer which would be a good thing, better braking authority for one.

But to just think of putting a WDH on a tow vehicle because someone says that's what they would do without reviewing the weight and balance of the current combination is just irresponsible.

Dave
All I did was ask a question. There were no recommendations made, irresponsible or otherwise. Bouncing is a sign of overloaded or nearly overloaded suspension. Knowing if there was a WDH or not to shift load off the rear and to the front of the TV is pertinent to the discussion
 
If you have two trailer axles, you will need to split them on different pads on the scale and weigh again to get individual axle weights. With two axles, you will have to weigh three times to get everything you need.
Total waste of time and effort! I know what you are referring to (and you don't even seem to know what to call that kind of axle) TORSION AXLES, such as found on Airstreams, Escape, some Winnebago Micro Minnies, and a few others. Truthfully, the vast majority of travel trailers have leaf spring suspension with an equalizer that the two springs attach to with the shackles.

If a trailer with independent functioning axles, such as Dexter torsion axles, is level, the load on the axles will be basically the same, give or take a few pounds. Get the tongue high, more weight goes on the aft axle of the tandems, and the trailer becomes more stable as you have more weight forward of that axle becoming tongue weight. If the trailer is tongue low, then there is more weight on the forward axle, and this puts more weight aft of that forward axle as the rear axle is not carrying its share of the load.

If the trailer is level, there is no sense splitting hairs over individual weights, and if its not level, it needs to be.

Charles
 
Total waste of time and effort! I know what you are referring to (and you don't even seem to know what to call that kind of axle) TORSION AXLES, such as found on Airstreams, Escape, some Winnebago Micro Minnies, and a few others. Truthfully, the vast majority of travel trailers have leaf spring suspension with an equalizer that the two springs attach to with the shackles.

If a trailer with independent functioning axles, such as Dexter torsion axles, is level, the load on the axles will be basically the same, give or take a few pounds. Get the tongue high, more weight goes on the aft axle of the tandems, and the trailer becomes more stable as you have more weight forward of that axle becoming tongue weight. If the trailer is tongue low, then there is more weight on the forward axle, and this puts more weight aft of that forward axle as the rear axle is not carrying its share of the load.

If the trailer is level, there is no sense splitting hairs over individual weights, and if its not level, it needs to be.

Charles
There was some guy on another forum awhile back who'd devised his own load tables for tires and was advising people to drive around with as low as 12 psi.
 
Ladies and Gentlemen:

I am familiar with torsion axles and weight distributing spring hangers. I intentionally made an effort not to use such technical terms for our newer colleagues who may not be familiar with the technical terminology. My intent was to answer an honest question with a simple explanation. I intentionally did not try to impress anyone with my command of the English vocabulary.

Good day.
Dave
 
Ladies and Gentlemen:

I am familiar with torsion axles and weight distributing spring hangers. I intentionally made an effort not to use such technical terms for our newer colleagues who may not be familiar with the technical terminology. My intent was to answer an honest question with a simple explanation. I intentionally did not try to impress anyone with my command of the English vocabulary.

Good day.
Dave
The OP asked about adding shocks to a travel trailer’s suspension. You volunteered an absurd method for determining Cat Scale axle weights.
 
Currently there are lots of videos (some good, some not so good) on the Shocker hitch for Weight Distribution systems. I am seriously considering this.

Shocker-Air-Equalizer-for-Weight-Distribution-Hitches.jpg


So yes, I'm going to revise my opinion somewhat. Really good shocks MIGHT help somewhat, but nothing is going to fix the problem of bad roads.

The OP DOES need to look at the shocks on his truck. They do wear out and they do leak. My RAM 2500 had the original shocks when I bought it, 86K mi and 18 years. The front right shock was leaking, the rest were worn out. I replaced them with KYB Mono Max, big mistake, not enough shock to dampen that big Cummins bouncing up and down. I went to the Rancho 9000 shocks and they work OK but nothing will help you when you hit the whoop-t-dos at the bridges on an interstate (those dips just as you go onto or off of the bridges). The front bump stops were also gone, had crumbled and only a little bit of them was left. I replaced them too.

I do know that a weight distributing hitch, set up properly, will dampen a lot of porpoising you experience towing.

OP needs to tell us a little more about his rig. Possibly we can offer some other suggestions.

Charles
 
Onyrlef:

Thank you for pointing out that I made a mistake in a post above. That should have been to put trailer axle number one on scale pad two leaving trailer axle number two on scale pad three by itself. I apologize for the confusion.

Dave
 
Onyrlef:

Thank you for pointing out that I made a mistake in a post above. That should have been to put trailer axle number one on scale pad two leaving trailer axle number two on scale pad three by itself. I apologize for the confusion.

Dave
There's no confusion. Where's the tongue of the trailer or the tow vehicle when the lead axle is sitting at the extreme back end of the scale? That's not how trailers are weighed. If you can take the total weight of axle 2 and 3 of a 3 axle tandem and divide by 2, you can take the total weight of a 2 axle tandem and divide by two.
 
You can add all the parts in the world to a trailer but nothing is going to help with these crappy roads we drive on. I have no idea why a bridge presents such an obstacle to road construction crews but they are terrible. As for trailer axle weights, well I don't think I've ever gotten that much useless information when it wasn't even asked for.
 
When splitting trailer axles, the trailer is hooked to the tow vehicle. The tow vehicle should be far enough forward to be off the scale pad that your first, or most forward trailer axle is on. That should be pad 2.

If the tow vehicle rear wheels are still on pad 2 with the axles split, you will have the rearward axle on pad #3 by itself. Then you can just subtract the rear axle from the gross axles to get the front axle weight. If you are on a ground level scale, you can pull forward to split the axles on scale pads #1 and #2.

If you are not on a ground level scale, I don't know if the weights would be accurate since the tow vehicle would already have started down the ramp so the trailer would likely not be sitting as it would be going down the road.

And you never want to disconnect a trailer on a scale. This is not done or should not be done. But don't take my word for it, ask the Weighmaster first and follow her instructions.

If you can't get axle weights, speak with the Weighmaster at the fuel desk and ask her if you can drop the trailer because you cannot get the weights you need. After you tell her of your problem, she may tell you to go ahead and do it. My guess is she won't, but you never know unless you ask.

It's possible there might be another option. Many CAT scales are a combination of four scales lined up next to each other. The assembly will just look like four scale pads. However, at many of these scale installations, the weights of pad #3 and #4 are summed together.

If you can find a scale where the Weighmaster can actually get the weight of pad #4 separately, you might be able to weigh your front trailer axle only on pad #4 just as you pull onto the scale. Then you can just subtract that axle from the gross axles to get the weight of the other axle.

Between the different scale installation and their computer software, you should be able to reasonably get axle weights. There are different way to juggle the weight figures to get the weights we need. And as long as your logic and math are correct. It doesn't make any difference how you get there.

There are plenty of ways to make the scale work for us. And they're all easy. Then we can compare the weights we get with our max weight limits to see if we are safe with a feeling of confidence that we make our trip comfortably and with no worries.

Dave
 
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When splitting trailer axles, the trailer is hooked to the tow vehicle. The tow vehicle should be far enough forward to be off the scale pad that your first, or most forward trailer axle is on. That should be pad 2.

If the tow vehicle rear wheels are still on pad 2 with the axles split, you will have the rearward axle on pad #3 by itself. Then you can just subtract the rear axle from the gross axles to get the front axle weight. If you are on a ground level scale, you can pull forward to split the axles on scale pads #1 and #2.

If you are not on a ground level scale, I don't know if the weights would be accurate since the tow vehicle would already have started down the ramp so the trailer would likely not be sitting as it would be going down the road.

And you never want to disconnect a trailer on a scale. This is not done or should not be done. But don't take my word for it, ask the Weighmaster first and follow her instructions.

If you can't get axle weights, speak with the Weighmaster at the fuel desk and ask her if you can drop the trailer because you cannot get the weights you need. After you tell her of your problem, she may tell you to go ahead and do it. My guess is she won't, but you never know unless you ask.

It's possible there might be another option. Many CAT scales are a combination of four scales lined up next to each other. The assembly will just look like four scale pads. However, at many of these scale installations, the weights of pad #3 and #4 are summed together.

If you can find a scale where the Weighmaster can actually get the weight of pad #4 separately, you might be able to weigh your front trailer axle only on pad #4 just as you pull onto the scale. Then you can just subtract that axle from the gross axles to get the weight of the other axle.

Between the different scale installation and their computer software, you should be able to reasonably get axle weights. There are different way to juggle the weight figures to get the weights we need. And as long as your logic and math are correct. It doesn't make any difference how you get there.

There are plenty of ways to make the scale work for us. And they're all easy. Then we can compare the weights we get with our max weight limits to see if we are safe with a feeling of confidence that we make our trip comfortably and with no worries.

Dave
The problem with this Dave isn't that anyone who knows how to use a Cat Scale knows that's not how it's done. The problem is someone might think it is.
 

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