Air Suspension - who knew?

[Tulecreeper]

^^^ this


This video shows the difference between a WDH and Airbags:

The Difference Between Using Weight Distribution and Air Bags to Level Your Load

Fastway engineers Jason Harper and Matt Barnes investigate the difference between using either a rear axle air bag system, or a weight distribution hitch to ...

youtu.be

I can't tell you how many "discussions" I've had with folks about this exact issue. I maintained a CDL for 30 years, and I've towed about every kind of trailer out there, but what do I know.

 

[crash68]

I can't tell you how many "discussions" I've had with folks about this exact issue.

Let me guess, they're favorite comeback line is: "but the truck is level" ... I've heard that many times.
I find showing them the video helps, a lot of people are visual learners, others learn when they get bit in the keester

 

[Tulecreeper]

Let me guess, they're favorite comeback line is: "but the truck is level" ... I've heard that many times.
I find showing them the video helps, a lot of people are visual learners, others learn when they get bit in the keester

Yep, but you and I know all they're doing is lifting the body. If you could measure the "squish" of the springs with the bags deflated before putting tongue weight on, then after the trailer is sitting on the tongue, then after inflating the bags they would see that the bags do very little to "un-squish" the springs.

 

[gwilburn]

But pumping up air bags only levels the body, it does little to stiffen the suspension or "redistribute" the load. Your springs/coils are still going to be squished down the same whether or not you use air bags. The only way to take weight off the rear axle and put some back on the front axle is with a WDH.

View attachment 532438

Wrong... these are not just airbags added to the suspension. The 4-corner air suspension IS the suspension. I do not have coil springs.

Adding air to an air suspension (even an air shock) absolutely increases stiffness.
Keeping the truck AND trailer level absolutely helps with weight distribution of the truck and the trailer.

I towed my trailer over 25,000 miles with my last truck alone... i towed the same trailer with many other trucks over the years. There is a HUGE difference.

 

[crash68]

Adding air to an air suspension (even an air shock) absolutely increases stiffness.
Keeping the truck AND trailer level absolutely helps with weight distribution of the truck and the trailer.

um..nope watch the video, it will visually show you that your wrong about the weight distribution. Doesn't matter if the truck has airbags on the front and/or rear.

 

[Tulecreeper]

Wrong... these are not just airbags added to the suspension. The 4-corner air suspension IS the suspension. I do not have coil springs.

Adding air to an air suspension (even an air shock) absolutely increases stiffness.
Keeping the truck AND trailer level absolutely helps with weight distribution of the truck and the trailer.

I towed my trailer over 25,000 miles with my last truck alone... i towed the same trailer with many other trucks over the years. There is a HUGE difference.

Even if that is true, just airing up the bags only lifts and levels the body. It does almost nothing to redistribute the tongue weight back to the front axle. Maybe some of the body weight, but the tongue weight is still resting on the rear axle. That would be like saying, "I lengthened my rear springs to push my body higher and redistribute more tongue weight to the front." Physics doesn't work that way.

But I'm out, so you do you.

 

[gwilburn]

Even if that is true, just airing up the bags only lifts and levels the body. It does almost nothing to redistribute the tongue weight back to the front axle. Maybe some of the body weight, but the tongue weight is still resting on the rear axle. That would be like saying, "I lengthened my rear springs to push my body higher and redistribute more tongue weight to the front." Physics doesn't work that way.

But I'm out, so you do you.

I didn't say it redistributed the tongue weight (which is negligible next to the truck weight). It does more than "level the body". It levels the entire truck AND trailer (and it is stiffer, like helper springs).
Making the whole rig level keeps both the truck and trailer happy - the correct weight is on the correct axles all the time. Keeping a trailer with tandem (spread) axles level makes a huge difference in sway.
Having said that, there is definitely a place for a weight distribution hitch - especially when the tongue weight is nearing the max.
And FYI, my degree is in Physics - so I'm fairly certain I know how "Physics works".

I can tell you BOTH @crash68 that the REAL WORLD difference with air suspension is noticeable even to those who don't tow often. Everyone wants to rag on the air suspension. I had it on my 2014 for 10 years and bought it again on my 2024.

As for the video... two engineers making a video to sell their product. Hmm, I'm sure it wasn't tailored to sell you on something.

 

[Cactusmonkey]

I have pulled 5th wheels and travel trailers for over 30 years, always used WDH and still do. In my opinion, the four-corner air is the best in so many ways. Leveling, handling and comfort. I have read some negative reviews on the system but I would order it again.

 

[crash68]

As for the video... two engineers making a video to sell their product. Hmm, I'm sure it wasn't tailored to sell you on something.

Apparently you didn't watch the video, they're not selling anything just explaining the difference in the physics of what each system does... having a degree is one thing, actually understanding how it applies is an entirely another concept that eludes some people.
No one is ragging on the Ram air suspension, just that some people have unrealistic ideas of what it does and it also doesn't have the greatest reliability track record.

 

[Tulecreeper]

Apparently you didn't watch the video, they're not selling anything just explaining the difference in the physics of what each system does... having a degree is one thing, actually understanding how it applies is an entirely another concept that eludes some people.
No one is ragging on the Ram air suspension, just that some people have unrealistic ideas of what it does and it also doesn't have the greatest reliability track record.

Agreed...I think the air suspension system is fine for smoothing out the ride and helping to level out the truck body, and in the process it also brings the trailer tongue up. It does not, however, transfer any weight off the rear axle and to either the front axle or the trailer axle which is what a WDH is for.

@gwilburn said : "The 4-corner air suspension IS the suspension. I do not have coil springs." I don't know anything about the suspension of the 1500 model, but having only air bags for suspension would make me nervous. Air bags have a tendency to fail - regularly. But he also said he has no problem with a WDH, so there's that.

 

[gwilburn]

Apparently you didn't watch the video, they're not selling anything just explaining the difference in the physics of what each system does... having a degree is one thing, actually understanding how it applies is an entirely another concept that eludes some people.
No one is ragging on the Ram air suspension, just that some people have unrealistic ideas of what it does and it also doesn't have the greatest reliability track record.

You should carefully re-read what I said.
Leveling anything will transfer some (vehicle) weight back to front of the truck... It also evens the load distribution on the trailer axles, AND helps a great deal with aerodynamic drag. This will help a great deal with handling, especially on slick roadways at highway speeds pulling a 28x6x8.5 v-nose enclosed trailer. Is it a replacement for a load distributing hitch? No. But it eliminates that sag you see from most of the trailers going down the road. It's a lot of work getting your rig level with traditional springs
Now, if I were pulling 8,000 or more with a 1500, I would want a LDH. I don't want or need one for 5500 lbs.
My physics degree is 35 years old... it's been a while, but I assure you I understand both Applied Physics and Mechanics. Heck, that's the easy stuff.

 

[Tulecreeper]

You should carefully re-read what I said.
Leveling anything will transfer some (vehicle) weight back to front of the truck... It also evens the load distribution on the trailer axles, AND helps a great deal with aerodynamic drag. This will help a great deal with handling, especially on slick roadways at highway speeds pulling a 28x6x8.5 v-nose enclosed trailer. Is it a replacement for a load distributing hitch? No. But it eliminates that sag you see from most of the trailers going down the road. It's a lot of work getting your rig level with traditional springs
Now, if I were pulling 8,000 or more with a 1500, I would want a LDH. I don't want or need one for 5500 lbs.
My physics degree is 35 years old... it's been a while, but I assure you I understand both Applied Physics and Mechanics. Heck, that's the easy stuff.

You mentioned that you tow a 6000# trailer, but you didn't say what your tow capacity is for your specific truck. There is a rule-of-thumb: If your loaded trailer weighs more than 50% of your tow vehicle's GVWR, you need/should use a WDH. Here is the tow chart for the 2023 1500 DS models, but it should be close for the DT also.

 

[crash68]

You should carefully re-read what I said.
Leveling anything will transfer some (vehicle) weight back to front of the truck.

I read what you said but it's WRONG!
You should have watch the video because it makes your statement of leveling with airbags transfers some weight back to the front axles completely false. Guessing physics wasn't your major.
The front axle looses more weight when leveled with airbags.
In picture format:

And just in case I cued up the video to where they show this:

The Difference Between Using Weight Distribution and Air Bags to Level Your Load

Fastway engineers Jason Harper and Matt Barnes investigate the difference between using either a rear axle air bag system, or a weight distribution hitch to ...

youtu.be

 

[PA Ram]

I read what you said but it's WRONG!
You should have watch the video because it makes your statement of leveling with airbags transfers some weight back to the front axles completely false. Guessing physics wasn't your major.
The front axle looses more weight when leveled with airbags.
In picture format:
View attachment 532655
And just in case I cued up the video to where they show this:

The Difference Between Using Weight Distribution and Air Bags to Level Your Load

Fastway engineers Jason Harper and Matt Barnes investigate the difference between using either a rear axle air bag system, or a weight distribution hitch to ...

youtu.be

Makes sense, I do not have an air ride suspension, but I did install load lifter 5000 ultimate plus airbags since I tow a camper regularly from March/April through late October or early November. I air up enough to bring rear up to untrailered ride height which takes about 50 lbs of air with trailer attached. I also have a weight distribution hitch with sway control. Rear airbags made towing a dream now. Steering was squirrely before installing the airbags.

 

[gwilburn]

I read what you said but it's WRONG!
You should have watch the video because it makes your statement of leveling with airbags transfers some weight back to the front axles completely false. Guessing physics wasn't your major.
The front axle looses more weight when leveled with airbags.
In picture format:

And just in case I cued up the video to where they show this:

The Difference Between Using Weight Distribution and Air Bags to Level Your Load

Fastway engineers Jason Harper and Matt Barnes investigate the difference between using either a rear axle air bag system, or a weight distribution hitch to ...

youtu.be

Physics and Math Double major... I'm "wrong" because I don't agree with YOU!

I've towed with and without air suspension, and with and without a load distributing hitch. Sorry, but I know what works in the REAL world.
You take ONE video of a few guys opinions on a SHOP FLOOR.

And Sorry if I'm not buying what they're selling.

 

[gwilburn]

Makes sense, I do not have an air ride suspension, but I did install load lifter 5000 ultimate plus airbags since I tow a camper regularly from March/April through late October or early November. I air up enough to bring rear up to untrailered ride height which takes about 50 lbs of air with trailer attached. I also have a weight distribution hitch with sway control. Rear airbags made towing a dream now. Steering was squirrely before installing the airbags.

Exactly... REAL WORLD EXPERIENCE

You mentioned that you tow a 6000# trailer, but you didn't say what your tow capacity is for your specific truck. There is a rule-of-thumb: If your loaded trailer weighs more than 50% of your tow vehicle's GVWR, you need/should use a WDH. Here is the tow chart for the 2023 1500 DS models, but it should be close for the DT also.

2024 1500 Ram Crew with 3.92s... I couldn't even tell you what the GVWR is. I've towed this trailer, at that weight with a 1/2 ton Ram for 22 years.

 

[Tulecreeper]

Exactly... REAL WORLD EXPERIENCE


2024 1500 Ram Crew with 3.92s... I couldn't even tell you what the GVWR is. I've towed this trailer, at that weight with a 1/2 ton Ram for 22 years.

Well, going by the attached chart your GVWR should be about 6900#.

 

[crash68]

Physics and Math Double major... s I'm "wrong" because I don't agree with YOU!

I've towed with and without air suspension, and with and without a load distributing hitch. Sorry, but I know what works in the REAL world.
You take ONE video of a few guys opinions on a SHOP FLOOR.

And Sorry if I'm not buying what they're selling.

No your wrong because the facts presented. The video is controlled testing of the difference in weight transfer between using air bags or a WDH.
The only person here being a jerk is the one who refuses to accept the facts because "they've been doing it this way for over 20 years". Trust me I don't go out of my way to tell someone their wrong unless I can back it with facts, which I've done.
If you don't want to believe the video, take your truck and trailer to a CAT scale, you can see it for yourself.

In the future, keep the name calling of any other member to yourself.

 

[TestPilot57]

Yep, but you and I know all they're doing is lifting the body. If you could measure the "squish" of the springs with the bags deflated before putting tongue weight on, then after the trailer is sitting on the tongue, then after inflating the bags they would see that the bags do very little to "un-squish" the springs.

Edit: I see someone else already addressed this.

But to those questioning suitability/reliability of only air suspension you may be thinking of supplemental airbags added to conventional metal spring systems. They are not engineered to be fail-point-averse systems. These are. There are 50,000 trailers with nothing more than air suspension systems. Metal springs can (and do) fail as well.

Original post:
1500s with air suspension do not have metal springs. Only the air "springs". I know this because if the system fails the truck sits on the bump stops. Same as happened with my 2009 MB CLS 500 with air suspension.

 

[Wmjohn]

Ive had air bags on my last 2 1500s and just ordered them on a 2024.

For the record, in a 1500, if you have air, there are NO springs, just air filled rubber bags or doughnuts.

With several hundred thousand miles driving on them, the ride is far softer than any spring suspension. I've never tried driving in the lowest mode so can't speak to any rough ride there.