Rear Suspension :: Airbags vs Helper Springs

[ntsqd]

With something like a Bilstein 7100 series damper you can change the shim stack to change the valving. I had to do this on the rear of my '84 Xcab when I swapped to 63" long GM 3/4t rear springs. Not because of a different spring rate, but because those springs have enough less internal friction to show up in the overall damping. Numerically the change wasn't much, from 255/70 shims to 278/75 shims but the difference in how the truck behaved was noticeable. These numbers are the force in Newtons need to move the shaft at one particular shock shaft velocity. Rebound first, Compression second.

With two different spring types, say leafs and air, you'll never get the damping very close. Each type of spring has unique needs in damping. As an example, in the 7100 series the std. off the shelf shim stack for leaf springs is 255/70. The std. off the shelf shim stack for coil springs is 360/80. One shim stack that I've seen for torsion bars was 345/135. I've no idea what air springs would want to start at, but I'd guess something close to coil springs. None other than Brett King, of King Shocks, told a good friend and savvy suspension tuner not to combine different spring types as he'd never make it work well in a serious Pre-runner style truck.

That said, I doubt many will want to abuse their campers hard enough to need that tight of a suspension tune.

I've seen air springs fail off road. I've seen them live and excel off road. It's dependent on the whole package; how are they driven, how were they installed, where were they installed (on the vehicle and by whom), what quality were they to start with, what kind of maintenance have they received since.

 

[Vic Harder]

Good to know about not mixing spring types. And about the flexibility of the 7100 series shocks. Thanks!

 

[sourdough]

This is out of character for me but I feel must chime in here and respectfully disagree after reading three posts bashing airbags.

I've been running Firestone Ride Rites for nearly a decade now as have many others without incident. I have not driven conservatively with them and have put them through about as extreme abuse one could expect with a camper on a vehicle without issue. I'm sorry, but I feel it is disingenuous to scare away newbies asking questions from using something that is actually quite capable. In short, airbags are not too fragile for off-roading.

Coincidentally a friend of mine and WTW member bought your old airbags when you sold them. It is our novice opinion that the cradles you installed with yours were the cause of your problems and actually pinched the airbag, just my opinion. Anyway, enjoy the new rig.

Pinching is a design flaw, now corrected on new units with internal bump stops that prevent pinching. Cradles where not the cause. No air in the rubber air bladder was the cause. Rubber airbags are fragile IMHO. And there are too many tubing connections and little hoses for air leaks. BTDT, give me spring steel.
Disingenuous, B.S. about what. I sold the bags, hoses,cradles and hardware for $60. I told you one was holed and needed replacement. There was no discussion about cause or effect. You think airbags are great, I do not. We all have opinions. How does any of this make me disingenuous.

 

[moveinon]

There continues to be discussion on here about whether airbags are weak as though it was just differing opinion. I have run air bags on a very modified off road truck that put on many miles in very tough situations without problems as well as my current Taco and camper without problems. If you do your homework on durability of air bags you will see that more than one car that has won the baja 1000 ran air bags. They obviously had a lot of suspension modifications like empi coilovers and other changes, but the durability of airbags is race proven -not just opinion. They also have air bag suspension built into a lot of sand rails and other dedicated off road rigs. And these are used for jumping, sometimes with a separate reservoir to reduce rebound. Tractor trailers run airbags all the time, so do dump trucks. These uses carry way more weight and get punished more than any camper and truck could withstand and they hold up. The bags are made by the same manufacturers that produce them for our trucks. In these uses failure is so small it is basically nonexistent. The issue with air bags is to purchase a quality bag and install it properly with quality air lines and fittings, which is very easy to do. If that it done they do not fail, if not they will leak or leak and fail.

 

[sourdough]

There continues to be discussion on here about whether airbags are weak as though it was just differing opinion. I have run air bags on a very modified off road truck that put on many miles in very tough situations without problems as well as my current Taco and camper without problems. If you do your homework on durability of air bags you will see that more than one car that has won the baja 1000 ran air bags. They obviously had a lot of suspension modifications like empi coilovers and other changes, but the durability of airbags is race proven -not just opinion. They also have air bag suspension built into a lot of sand rails and other dedicated off road rigs. And these are used for jumping, sometimes with a separate reservoir to reduce rebound. Tractor trailers run airbags all the time, so do dump trucks. These uses carry way more weight and get punished more than any camper and truck could withstand and they hold up. The bags are made by the same manufacturers that produce them for our trucks. In these uses failure is so small it is basically nonexistent. The issue with air bags is to purchase a quality bag and install it properly with quality air lines and fittings, which is very easy to do. If that it done they do not fail, if not they will leak or leak and fail.

I don't believe a modified race trunk or a sand buggy set up for jumping or a 18 wheeler has any relevance just because they have air bags. Comparing there mounting systems to an overloaded stock truck and camper running a universal bolt on over the counter air bag kit is wrong.
I totally agree with, when bag leaks they can and do fail. The bag is tough, the supporting hardware not so much. They now have an internal bumpstop that keeps the bags from over compressing due to low or lost air.
A race truck, sand buggy or 18 wheelers are set up with a external bump stop factoring in bag compression before total air bag compression and pinching.
This thread is not talking about anything but over the counter universal air bag kits. It is the supporting hardware and hoses in the over the counter kits that are fragile and cause the bag to fail.
My properly installed over the counter stock kit failed. The failure left me limping 40+ miles to get repairs only to find it would be days out for a replacement bag. I had the bags and all the hoses and hardware pulled and replaced with steel springs. I sold the camper and kept the spring kit http://www.activesuspension.com It works like a sway bar also.

 

[ntsqd]

I think their other uses are relevant. It shows that they work and live in situations that get worked hard. The air spring doesn't know if it's being compressed by a jump landing or because it's under an 80k lbs OTR truck. I would go further to say that the jump landing is more strenuous to the air spring than anything a truck with a camper will ever put one through.

No experience, so no comment directly on the mounting systems. From experience I will say that it is easy to design things that appear to be robust enough for the application and should be based on similar experiences, but reality proves different from what was expected and the design is a failure. The need for an internal bump-stop shows that the bracket system wasn't designed well. A good design would have used the OEM bump-stop and avoided being pinched even when that was metal to metal.

Maybe you're not talking about hoses & fittings other than supplied, but as a designer who first was working with hydraulics and now with pneumatics (not to mention race vehicle plumbing) I would be VERY disinclined to use anything supplied in a kit if if it were not up to industrial/production part standards.

All of that said I'm not a fan of air springs being used full time to supplement a leaf spring suspension. Each type of spring has it's own unique damping needs. Mixing types in on suspension means that the damping curve will never, ever be right. Maybe a truck with a camper will never be pushed hard enough to need damping that well tuned, but I still find it offensive and will resist doing it if at all possible.

The same can be said for that add-on coil spring system. I think that it is an abomination. It puts loads in parts never designed to be loaded that way, and it can not add roll stiffness (sway-bar) only spring rate. For the cost of that system and it's install the rear leaves could have been rebuilt or replaced with leaf springs designed for the job. Deaver, Alcan, and Valley are at least 3 names that can perform this work.

 

[SunMan]

Pinching is a design flaw, now corrected on new units with internal bump stops that prevent pinching. Cradles where not the cause. No air in the rubber air bladder was the cause. Rubber airbags are fragile IMHO. And there are too many tubing connections and little hoses for air leaks. BTDT, give me spring steel.
Disingenuous, B.S. about what. I sold the bags, hoses,cradles and hardware for $60. I told you one was holed and needed replacement. There was no discussion about cause or effect. You think airbags are great, I do not. We all have opinions. How does any of this make me disingenuous.

Not implying there was anything shady about the sale, my friend wanted the hardware only, he knew what he was buying, the one good airbag was a bonus as he has a spare if he ever needs it. He ended up selling the cradles.

All I am saying is that you telling a newbie asking questions that airbags are fragile and not suitable for off-road is simply not true. I would hazard a guess that the majority of people on this forum have airbags and use them off-road. I'm sorry you had a bad experience with your bags but that does not mean they are fragile. Everyone needs to make their own decisions as to what best suits their needs, for myself and many others, airbags fit that requirement.

 

[sourdough]

After market air bag kits sold over the counter are fragile and not designed for off-road use. Custom off-road air bag suspension systems are designed for off-road use.
Roadster Active Suspension reviews....https://www.google.com/#q=roadmaster+active+suspension+review

 

[Rockcod]

Thanks to everyone for the options and contributions to this thread. My timing allows me to figure out suspension needs first and this sure helps.

 

[sourdough]

A truck loaded over it's rated GVW will never be safe just installing an aftermarket spring helper. Be it air bags or overload springs.
Statement below is from here....http://riderite.com/Ride-Rite%20Product%20Detail

Ride-Rite air helper springs enhance the ride by reducing inter-leaf friction. Please remember that air springs do not increase the loadcarrying capacity of your vehicle. *DO NOT EXCEED THE VEHICLE’S RECOMMENDED GROSS VEHICLE WEIGHT RATING (GVWR


What Is Covered:
This warranty does not apply to Ride Rite Air Spring Assemblies that have been improperly applied, improperly installed, used in racing or off road applications or used for commercial purposes.

 

[knoxswift]

My setup is a 2010 Tacoma with Eagle FWC. 3" lift total with this setup.
I'm always at the GVW but since I can't afford a new truck right now my setup is the following for FULL TIME install of the FWC. I'll hopefully replace this truck in another 5 years.
This setup is also designed for 4Wheeling with the camper installed to boondocks sites both rock crawling and desert. It's not setup for mud but I've done a few trips successfully with no winch.
If I remove the FWC, it drives terrible but that's not too often only when I need to do some home depot type runs or bring a motorcycle to a shop or something.

Hellwig Progressive Spring Pack for FWC
http://www.hellwigproducts.com/new-products/4231/

Roadster Active Suspension Kit for Sway:
http://www.activesuspension.com

ICON Hydraulic Bump Stops
http://iconvehicledynamics.com/shop/individual-components-and-accessories/403-2005-current-toyota-tacoma-rear-hydraulic-air-bumpstop-system.html

ICON Stage 1 Front
http://iconvehicledynamics.com/shop/complete-suspension-systems/187-2005-2015-toyota-tacoma-0-35-suspension-system-stage1.html

Total Chaos UCAs
http://www.chaosfab.com/2005-2013-Tacoma-Upper-Control-Arm-Kit-96504.html

 

[allanb]

Thanks Sunman. You helped at a good time for me. From all I have read here and on other forums, the vast majority of folks use and swear by airbags. I was getting ready to buy some and one voice had a bad experience with them. You helped clarify it for me, and I am still sure they are the way to go. I will double check the hardware and hoses though Sourdough.
I will have the camper on 90% of the time. But there a good chance it will come off at some point to pull a trailer for a while. So doesn't make sense to have new springs installed. The worst roads i'll be doing are gravel and forest service dirt. No baja or overland expo stuff.

 

[abqbw]

I had a new FWC hawk shell model (1153 lbs) installed on my 2011 Tundra double cab on Sept 6 this year. Since then I have driven from Jackson Hole, WY to Albuquerque, NM and down to the Gila National forest (twice) from Albuquerque. I've been on two elk hunts (WY and the Gila in NM) and an elk scouting/photographing trip (the Gila). I squeezed in a side trip to Rocky Mtn National Park.

I've driven every kind of road imaginable fully loaded. From 80mph interstates, windy mountain and canyon paved roads, fast gravel all weather roads with lots of washer boards, fairly gentle two-tracks, to very rough uneven rock crawling roads. My suspension has performed flawlessly. I will not change a thing. My suspension consists of a Toyota factory TRD pro suspension that I had installed last year by the Toyota dealer (kit consists of new struts/springs in the front and rear shocks). I added eckstrom design 1-3/4 shackles in the rear because the TRD pro suspension raises only the front 2" and I wanted to maintain the factory rake. I had my rear springs replaced to accommodate the camper. The work was done by Boise Spring Works in Boise, ID who was recommended by my dealer, Denny Saunders of FWC of Jackson Hole. I wanted to try to avoid air bags because I spend a good deal of time on very rough 4 wheel drive roads. The spring work consisted of removal of the shortest bottom factory leaf and adding 4 new leaves for a net gain of 3 leaves. The TRD pro suspension works so well because it has a lot more articulation than stock. I didn't want to give that up.

I am surprised and very pleased at how well my truck handles on road and off-road with the camper. I drive pretty fast. Too fast probably. With all the variable driving conditions I have driven in I think I have done a thorough suspension test...


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[buckland]

With this set up do you take the camper off for any time and how is the new spring leaf pack feel w/o the camper on?

 

[abqbw]

I haven't driven it much without the camper. I just had the spring work done and the camper installed in early September. After the spring work, I drove the truck empty in Boise for a half a day and then the 375 miles to Jackson to have the camper installed. It wasn't particularity rough riding. It was stiffer but not harsh. I was actually worried that it wouldn't be "stiff" enough for the camper because the ride didn't seem very stiff. It turned out that it supports the camper perfectly.


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[buckland]

Is this a Progressive spring pack that only 'kicks in' when the overload spring should (which was removed)?

 

[daverave]

I'm having some Firestone air bags installed on my Hawk/F-150 4WD rig next week but am curious as to whether there needs to be adjustments made to them as one drives from sea level over 8,000 foot mountain passes? Most of our trips from Sacramento involve at least some time at higher elevations whether our destination is the Sierra or the desert. Is there a noticeable difference in the ride as the vehicle gets higher due to the potato chip bag effect?

 

[rando]

I'm having some Firestone air bags installed on my Hawk/F-150 4WD rig next week but am curious as to whether there needs to be adjustments made to them as one drives from sea level over 8,000 foot mountain passes? Most of our trips from Sacramento involve at least some time at higher elevations whether our destination is the Sierra or the desert. Is there a noticeable difference in the ride as the vehicle gets higher due to the potato chip bag effect?

The is not something you need to worry about. The pressure at sea level is ~1000hPa and at 8000' it is about 750hPa. The change of 250hPa is equal to about 3.5 PSI - so your air bag (gauge) pressure will only increase by 3.5 PSI - not enough to notice. Depending on how much pressure you are running in the bags, you pressure may actually decrease more from the cooler temperatures at altitude than it appears to increase from the change in atmospheric pressure.

 

[hebegebe]

I have found that driving in the heat can swell the airbags and make them harsh an in cab gauge and valve allows you to bleed air off a bit when that happens


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[allanb]

no problems or notice any difference in ride. Driven about 3000 miles in last 4 weeks, from 0 feet elevation, to 10000 colorado passes.