So, was considering some air bags to kill the porpoising I get on the wonderful interstate bridges in my state when towing heavy. I never thought of getting them before as the truck sits level with 3200 or so of pin weight on it but my recent post about spring fatigue got me thinking about some help back there. I see there are three kits out there. One from Firestone and two from Airlift (with and without an internal jounce bumper.) I really liked the idea on the one with the internal bumper as you can leave the bag completely empty without fear of damage. Since I'll only run air in them 3-5 times a year when towing the toyhauler, that would be convenient rather than maintaining 5lbs in the ones without the bumpers.

My concern is this. I wrote to the tech guy at AirLift and asked about this application. My worry was I didn't want the bumper to come into contact on rough/bumpy roads when the bag was empty and jolt the rear end. I have noticed this in the past when the helper springs do the same and didn't want to double up on the jolting/bumping. Mike thought this might be a real worry and suggested I stay with the standard bags with no bumpers for the smoothest/stock like ride while unloaded and aired down.

So, has anyone actually installed the new style with the bumpers? If so, do you feel the bumpers bottom over bumps and get a jolt while aired down? Any experience with these would be appreciated.

 

The bumper inside the air ride bag is made of urethane foam, so I imagine it works like a progressive spring itself. Since all 11+ kits mount where the factory bumpstop was, the bag has now become the bumpstop and will take the abuse of hard limiting suspension compression under worst case conditions. The bags themselves are fairly robust, and I havn't read much about failures due to this.

Personally, I think the bags in all three kits limit suspension travel too much, so I can't reccomend one over another.

Airing down the tires will have a much larger impact on bumpy roads than air bags. Well, I guess a tire is a doughnut shaped airbag. Mmmm. doughnuts...

 

Just a comment about the suspension travel. Most around the 6.7 forum know that I take my truck off road often and pulling a 25' enclosed trailer with 5 four wheelers in it. Take my word as a grain of salt, but I use my truck hard and also maintain it as well and actively as I can. I bought airbags with the idea that I would tear them up off road or limit my travel. It's been a year and likely 30 trips (in not so nice conditions when a truck with normal tires and no lift repeatedly have gotten stuck) and have yet to get stuck or damage a bag. It might be a concern if you are racing, but for average off-roading the loss of articulation for me hasn't been a problem. Now if someone can keep my kids from getting flats on their four wheelers, I'm all ears.

 

Foam filled tires Andre.....or solid rubber and watch em enjoy the ride!!

 

The biggest concern with the airbag kits I'm familiar with (Firestone 2535 in my case) is that they straddle the jounce tongue on the rear lift block and therefore limit suspension travel because they sit so high. Since the jounce bumpers have to come off anyway, I removed the lift blocks and removed the tongues with a plasma cutter and then ground them down smooth and re-painted them. It was easy for me because I have a shop and the appropriate equipment. By doing this I have 6-1/2 inches between the upper and lower mounts with the bags deflated and the truck unloaded. I've also had one of the lower mounting brackets roll forward under load because that little low grade U-bolt can only provide so much clamping force. The simple solution to this is to tack weld a piece of 1/2 key stock (about 2-1/2 to 3" long) to the axle on either side of the bracket.

 

Air bags are great. I originally put them on my 04 F 250 to level out the truck when hauling my fifth wheel. The first thing I noticed was that it got rid of the bouncing that you talk about. When I bought my 2012, the first thing I did was put those bags on it. I have the Firestone Ride Rites, but I imagine the Air Lifts are just fine too.

 

Not to be a dick, but thanks guys for a bunch of replies that have nothing to do with my question.

 

I have installed some of their new style bags (5000 ultimate I believe), just not on our body style. With no air pressure you will not know anything has changed, and you keep the safety of the factory style bump stop. I'm going to put a set on in the spring before the camping season gets underway and do a full report.

 

My experience was the opposite...

While I was toying with the internal bumpers, I got the standard bags for the 12 250 and immediately noticed a degradation in ride even with just 5 psi in the bags....

Thus far the 13 350 has not needed bags and rides better IMHO... (no scientific metrics, just seat o de pants) YRMV

but will follow your thread to see if anyone else inputs !

 

Thanks guys!! I have done Firestone bags on my 09 250 and could not tell they were there with 5 lbs in them so I'm surprised that jdadamsjr had trouble with a similar product. Hopefully my experience is similar to Chad's as I think I will try the one's with the bumpers. Another thing that Andre pointed out to me is this. I plan on skipping an onboard compressor as I'll only use mine a few times a year for towing. I have an air bag in my pinbox so I'll just fill the bags on the truck when my compressor is out for the pinbox. The one's without bumpers would be a pain as all bags loose air and I'll need to keep checking and refilling manually when not in use to avoid damage.

 

Karl,

I went on board compressor for the reason stated, but also because 5 psi in 80 degrees is about 3 in 50 degrees. Those new bags came oit 6 months after my install, but would like to know the answer to your question by a real user.

Can the folks that sell the bags with internal bumper tell you how tall it is? If it is not as tall as the free-play you have before your override spring takes over, you should get what you are looking for. My 450 is 4 wheel drive, but not "off road" model. My free-play is a full 1 inch less than 250s, 350 SRW, and 350 DRW models. Mine is 2.5 inches, most others mentioned are 3.5 inches because of the stock block on the spring pack. I also had 1 less inch of sag before i hit the rock hard stock axle bumper that is removed with the air bag install.

I find that cool morning 10-15 psi is all i need to keep me level loaded. This immediately becomes 30-35 psi with 3600 pin. A day of driving and warmer air brings this to about 40 psi and all is well. Any more than 40 psi and the ride is too hard. Without the 5er, that 10-15 psi is a pretty rough ride over speed bumps, but if i am just unhooking to go out to dinner or go shopping, i leave it at the 5er setting. If i am going on a longer empty run, or not hooking back up for 3-4 days and expect several short trips, i deflate to 5 psi.

I say find out how tall the internal bumper is. If ok, or actual user say no porpoising, great. If not, go std bags but put in the cab gauge. You would air from your compressor to the bags, but you can tell at a glance if you have an issue with loss of air. If later you find you want on board compressor, half the work is done (if you spring for the gauge with inflate/deflate ***** versus simple gauge).

 

John, I really wish AirLift had better info. Their tech guy admitted he was guessing as to whether there would be contact with the internal bumper unloaded and aired down. You would think the guys who made it would know. I know AirLift has an account here and was wondering if the person who used it would be the same as the tech guy who answers the phone/emails, or maybe someone higher up that would know more about my specific question? Chad did say he had first hand experience with the bumper style and that there was no noticeable jolt but it looks from his post like it's not his personal truck? So, that makes me wonder if more driving/personal experience could expose more jolts???

 

Sounds like AirLift should give you a set of these new bags to beta test...

 

What in the world could you be talking about? Outside of extraordinary circumstances, how can mostly empty air bags affect the ride at all? It's basically like they're not there. What kind of degradation did you sense?

 

EXACTLY! Maybe you should start a post about it to get their attention Andre. Use the word "prolly" in the title and it's sure to get some play!