Camper/overload springs/and more

[brillmtb1]

So I have been tinkering around with airbags (already installed for my 5th wheel prior to gettingcamper), overload springs, better adjustable shocks, added rear sway bar and commercial 19.5 tires to get my camper to ride better. Its one of those very nice but heavy AF 911.

I took out my 2inch lift up front so that I could sink the camper into the overloads and that is better but now I want to run my larger tires sometimes. With the overloads I just got, sent back others as they didnt do much but the new ones look much better with two settings, they say my truck might now ride an additional 2 inches up. Since stock is already there, I am thinking of adding front springs with a 1.5-1.75 lift, Thurens. They are also a little softer. Since I weighed my truck at a CAT scale with the camper on I noticed almost no weight goes up front to the lift and softer spring with my adjustable shocks my allow for versatility in tire clearance as I do take the 19.5 off over the late Fall- winter as I live in snow country.

The end result may be still a 2.5 inch higher rear but higher front to clear my larger tires without headlights in people's faces

Thoughts?

 

[Turbo Terry]

How much does your camper weigh

 

[brillmtb1]

Too much. 4k wet

 

[AH64ID]

Where are you trying to create clearance for larger tires? What size tires?

Knowing your setup I wouldn’t lift the front at all, and certainly not softer coils. You would likely hate the loaded handling and sway.

What rear overloads did you get?

 

[brillmtb1]

Springs rated to 4k. Not so sire softer front that much an issue as weight all on the back

 

[lpennock]

Are you Level or butt up when loaded. If level I wouldn't do anything. If butt up I would only raise the front enough to level or stay slightly butt up.

 

[brillmtb1]

When i put in the stiffer overloads o anticipate being up an inch or more

 

[AH64ID]

Springs rated to 4k. Not so sire softer front that much an issue as weight all on the back

Side to side sway is still effected by the front springs.

I want to make sure I’m following. 4K rated overload springs, and airbags that are likely rated at 5K. Seems redundant, and excessive, even with 19.5’s. I say that because I ran 19.5’s and airbags on my 05, which had the softer 3/4 ton main leafs and DRW overloads. At the 19.5 wheel ratings the airbags were more than adequate for leveling the load, with a 1” level kit.

Your 3500 has a stiffer main pack than my 05 3500 had. So my point is that if you need the stock springs, 4K overloads, and airbags then you are either overloading the 19.5’s or mixing too many suspension enhancers and complicating the setup.

With a higher CG load the last thing you want to do is lift the truck, it’s a great way to reduce handling. You want that load as low as possible.

If it were my truck I would stick with stock front springs. I would remove the aftermarket overloads, and utilize just the airbags with an aftermarket rear anti-sway bar. That will keep the load the lowest, while proving the best side to side stability.

 

[Turbo Terry]

Something tells me maybe you need a dually for that much weight

 

[brillmtb1]

Airbags should never be used with a camper in my and others opinion. Takes the weight off the outboard springs which handle weight and roll much better. Lifting the back with overloads allow the heavy camper to squat down. This in my opinion has created the best sway control. 19.5s dont complicate. They allow for 9000 load and stiff sidewalls for sway conteol

when i ran airbags only i was white knuckle driving as the bags were trying to control the weight and roll. Just horrible. Great for a fifth-wheel but nit a camper

 

[SnoKing]

Airbags should never be used with a camper in my and others opinion. Takes the weight off the outboard springs which handle weight and roll much better. Lifting the back with overloads allow the heavy camper to squat down. This in my opinion has created the best sway control. 19.5s dont complicate. They allow for 9000 load and stiff sidewalls for sway conteol

when i ran airbags only i was white knuckle driving as the bags were trying to control the weight and roll. Just horrible. Great for a fifth-wheel but nit a camper

And blow an air bag and over you go!

 

[bcbender]

4K rated overload springs, and airbags that are likely rated at 5K. Seems redundant, and excessive,

I would agree here, for my 5er, the overloads were terrible.. Air bags much better, but in this case perhaps the overloads are what you want. I think the point is don't run both as you will not get the benefit of either when they are doing 1/2 to 1/4 of their job. Also I assume you are using a rear anti sway bar to help with that roll?

 

[AH64ID]

Airbags should never be used with a camper in my and others opinion. Takes the weight off the outboard springs which handle weight and roll much better. Lifting the back with overloads allow the heavy camper to squat down. This in my opinion has created the best sway control. 19.5s dont complicate. They allow for 9000 load and stiff sidewalls for sway conteol

when i ran airbags only i was white knuckle driving as the bags were trying to control the weight and roll. Just horrible. Great for a fifth-wheel but nit a camper

The main reason people have issues with airbags is that they overfill them and try to get the truck back to empty, or near empty height. This does create the handling you are describing.

When used properly they don’t have that effect, and helps reduce sway as well. They only take too much weight off the springs when they are overinflated.

19.5’s certainly don’t complicate, all you have going on with the suspension does.

You never said what size tire you’re trying to run, and why you want a lift/level.

And blow an air bag and over you go!

lol

 

[lpennock]

When used properly they don’t have that effect, and helps reduce sway as well. They only take too much weight off the springs when they are overinflated.

As usual I'm going to disagree with you John. Air bags will never provide the sway control that the spring packs provide. I do agree if you don't take too much weight off the spring packs they won't hurt it too bad but since they are removing load from the springs they will increase the sway with high COG loads like truck campers. It is simple moment arm physics, 2ft moment arm vs 3ft moment arm meas the airbags only provide 2/3 the sway control that the springs provide or to put another way for ever pound of load you take off the springs you are decreasing your sway by 3/2 of a pound.

Using air bags with a truck camper requires a rear sway bar IMO. My 06SRW with Torklift upper stable loads and no rear sway bar had less sway than my 18 DRW with factory air until I added the roadmaster swaybar to the 18. I will admit I have no experience with a 5er which is your area of expertise so that may be a different story as the loading on the truck is different than with the truck camper.

 

[kthaxton]

I also question the desire for lifting and installing bigger tires for something that is carrying a camper.

 

[Cummins12V98]

Something tells me maybe you need a dually for that much weight

i was holding back on that same comment but hey as they say X2!!!

 

[petersonj]

How much does your camper weigh

Too much. 4k wet

I think that statement is too generalized. Need front axle and rear axle weights when loaded with the camper and supplies for a typical trip.

Also, is your truck a long wheel base or short wheel base?

I could not find the Arctic Fox 911 camper that you mention - does this camper have a basement? If so, the center of gravity situation will be exacerbated.

You mention Rancho adjustable shocks. Are they the Rancho 9000 9-way adjustable series?

I used to own a heavy truck camper with a basement (Citation by General Coach) for a number of years and I had the same concerns as you. I carried the camper with the truck in my signature. It is a long wheel base truck. The truck was equipped with factory anti-sway bar (front and rear), overload springs, after market airbags, and Rancho 9000 series 9 way adjustable shocks. The tires were stock Michelin 265-75R/16's

Empty:
* front axle - 4,400 lbs
* rear axle - 3,050 lbs
* total - 7,450 lbs (driver only)

Camper and gear
* front axle - 4,850 lbs
* rear axle - 6,150 lbs
* total - 11,000 lbs (two people)

I think it is important to have some of the camper weight transferred to the front axle.

I inflated airbags to 30-40 psi - never more.

It took some time and experimenting to get the loaded truck to handle well. In my case, the one single adjustment that mattered most is not mentioned here - adjustment of the shocks.

I found that I needed to adjust the rear shocks to #8 (one less than the heaviest setting) and the front shocks to #5 (mid-range setting). This adjustment was crucial - it allowed for the rear, heavy high center of gravity side to side return travel to be matched with the front, lighter low center of gravity side to side return travel. With these settings anytime the truck was pushed to one side or the other (due to curves, wind, roadway, etc.) the cancellation of the lean was quickly dampened.

I would definitely try to keep the center of gravity as low as possible and use the airbags only as an assist (low air pressure) I would not install softer springs on the front axle. When you are braking, camper weight quickly gets transferred forward - you need the ability for the front suspension to handle that transferred weight.

I have since sold that camper and I now own a travel trailer. The combined weight of the truck and travel trailer is 12,500 lbs (1,500 lbs more than the truck / slide in camper combination), but it handles SO MUCH better! Plus, I now have two more braking axles.

- John

 

[AH64ID]

As usual I'm going to disagree with you John. Air bags will never provide the sway control that the spring packs provide. I do agree if you don't take too much weight off the spring packs they won't hurt it too bad but since they are removing load from the springs they will increase the sway with high COG loads like truck campers. It is simple moment arm physics, 2ft moment arm vs 3ft moment arm meas the airbags only provide 2/3 the sway control that the springs provide or to put another way for ever pound of load you take off the springs you are decreasing your sway by 3/2 of a pound.

Using air bags with a truck camper requires a rear sway bar IMO. My 06SRW with Torklift upper stable loads and no rear sway bar had less sway than my 18 DRW with factory air until I added the roadmaster swaybar to the 18. I will admit I have no experience with a 5er which is your area of expertise so that may be a different story as the loading on the truck is different than with the truck camper.

It's hard to compare the 3500 SRW with upper overloads to the current 3500 SRW's that don't have them, those upper overloads were impressive, thou they were generally unneeded on a stock SRW as they didn't come into play with stock suspension (no upper stable loads) until after the tires were overloaded. I can see why they ditched them in 2010, but modified they were pretty awesome on a SRW.

The airbgas are ~17.5" from center and the main leaves are ~25.5", which as you said makes a big difference in control and why overinflating airbags is such a disadvantage. One large advantage to properly inflated airbags is the variable spring rate (more per inch than the steel springs have) when plumbed independently. When you get sway the side that compresses gets a higher spring rate and the side that extends gets a lower spring rate, this helps reduce the sway more than the static arm measurements indicate. When the airbags are overinflated it doesn't work as well nor when they are plumbed as a single unit. Arm is very important, and why the '14+ 2500's get such a large benefit from airbags as they are much more outboard than the narrow OEM springs. This is also likely part of the reason the C&C springs are much more robust on a 3500 C&C vs a pickup, despite lower RAWR's. The C&C frame is 8" narrower, the same difference as the airbags to the main leaves.

A 5th wheel is my current setup, but not my only experience. Carrying ATV's above the bed rail and airbags made a huge impact in sway control, with an anti-sway already installed but the stock '18 handled that high CG weight better than the modded '05 did. I also have quite a bit of time messing with dad's 06 that hauled a camper at approx 8K RAW, which was setup wrong for a slide-in despite him know it.

I'm not sure I'd want to run a large hard side without a rear-anti sway bar, irregardless of the suspension setup.

 

[brillmtb1]

So to clarify. I like to switch tires during a season where I would not camp such as late fall-winter and I go with my KO2s 295/65-20 which are rated at about 4000lbs so can work with my 7000lb rear with camper but I never like running things to the near max hence the 19.5 rated at something like 4500-5000 each, much stiffer side wall which adds more than just weight capacity and they supposedly run cooler and longer under heavy loads.

As far as the airbags I put them in for my AF 27-5L 5th wheel and they were perfect. Used alone on the camper and they are scary to say the least. I added the sway bar but with this load and tall camper it wasnt enough. Went to the Rancho 9 way adjustable and set exactly as stated above with overload springs and no air in the airbags and MUCH MUCH better. I could add a little air like 30lbs but I feel the overloads really helped.

Next I am thinking of adding back front spring or put back in my 2inch block to run the larger tires I have without scraping too much and with the new overloads that will go back in this spring the truck will be near level when loaded as my camper drops the truck somewhere around 3 inches.

So the only hassle I see here is changing the tires each season but I am ok with that.

As far as a dully, my understanding is that the rear weight capacity axle wise is identical but I would then need a long bed and since I camp much less than I daily drive that would not be ideal for me unless I get that new 4wd hybid corvette coming out soon

 

[AH64ID]

You should not need any lift to run that tire without rubbing. What wheels are they on?

You said the rear drops 3" with the camper, which means you should be about level at that point. A 2" front spacer would make you ride nose high.

Out of curiosity what pressure did you run in the airbags when you first got the camper, how are they plumbed? And was your 2" front spacer still installed?