Air ride!
I just installed an airbag suspension on my new '15 F350 dually and took it on the first camper trip. I will put at the end of this post the reasons for doing it to save the long narrative for those i...
Forum Discussion
At the top I had promised a long boring tome about why I did this and why I picked this kit. Please skip it if you have no interest:
My new '15 F350 dually seemed to ride rougher both empty and with the camper loaded compared to the '99 it replaced. The '99 was already rough enough. In order to level the old truck, I had to install airbag assists and these are generally a poorly engineered solution. In spite of its rougher ride, the new truck sags at least as much with the camper, it would at a minimum require re-aiming the headlights each time it was loaded. Rather than once again add the usual suspension bandaids I determined to replace the springs entirely.
No one in the US currently makes an airbag replacement suspension for the 2WD dually pickup. Sketching out my own design it becomes clearer why: there is very little room left for the airbags and links required. 4WD or chassis cab increase the height or width available and make it easier, Kelderman will make something for both configurations, but not a 2WD pickup. The Kelderman requires some modifications to the truck as well, which I wanted to avoid for two reasons - it may void the warrantee on some components, and it makes reversing the conversion more difficult if it turns out not to meet expectations. I have low expectations for aftermarket kits and equipment, nevertheless you would like overall to improve things and it isn't always the result with such kits.
In searching for a kit I ran across Autoflex, a Canadian company that has been doing these conversions for a long time. Their website and online reviews describe a system similar to heavy trucks, essentially a swing arm bolted to each side of the axle with an airbag behind it. I was impressed by the solutions Autoflex had come up with to solve some of the problems with this type of system, the clever way it was designed to be strictly bolt-on, and how it fed all of the loads into the frame exactly as Ford designed. However any swing arm suspension will suffer torque reactions from acceleration and braking that I did not want, especially on a truck with this much available torque. Out of curiosity I contacted them about it.
I was pleasantly surprised to find that they have more recently introduced a 4-link plus Panhard rod version, which by its nature eliminates the torque reactions. This is similar in type to the Kelderman, though a lot different in detail: they kept many of the clever features which made it a bolt on conversion, and they assured me they could do it to fit a 2WD dually. I grilled them a number of times on the phone about clearances, strengths, etc. I did my own engineering analysis on it. Their approach is not really a theoretical engineering oriented one, more a product of long experience building logging trailers and hundreds of air suspensions installed in emergency vehicles. They seem to know what works and what breaks. For the most part, each question I asked had an answer with reasoning and experience behind it. The shipping from Canada is expensive, so I figured I was probably stuck with it once ordered. In the end I decided it was close enough to what I had drawn for my own design to buy it as a starting place - I could always modify it if needed. So far, I have a couple of interference problems unique to the 2WD dually which I am confident will be resolved, I don't think I would change a thing with the design.
My new '15 F350 dually seemed to ride rougher both empty and with the camper loaded compared to the '99 it replaced. The '99 was already rough enough. In order to level the old truck, I had to install airbag assists and these are generally a poorly engineered solution. In spite of its rougher ride, the new truck sags at least as much with the camper, it would at a minimum require re-aiming the headlights each time it was loaded. Rather than once again add the usual suspension bandaids I determined to replace the springs entirely.
No one in the US currently makes an airbag replacement suspension for the 2WD dually pickup. Sketching out my own design it becomes clearer why: there is very little room left for the airbags and links required. 4WD or chassis cab increase the height or width available and make it easier, Kelderman will make something for both configurations, but not a 2WD pickup. The Kelderman requires some modifications to the truck as well, which I wanted to avoid for two reasons - it may void the warrantee on some components, and it makes reversing the conversion more difficult if it turns out not to meet expectations. I have low expectations for aftermarket kits and equipment, nevertheless you would like overall to improve things and it isn't always the result with such kits.
In searching for a kit I ran across Autoflex, a Canadian company that has been doing these conversions for a long time. Their website and online reviews describe a system similar to heavy trucks, essentially a swing arm bolted to each side of the axle with an airbag behind it. I was impressed by the solutions Autoflex had come up with to solve some of the problems with this type of system, the clever way it was designed to be strictly bolt-on, and how it fed all of the loads into the frame exactly as Ford designed. However any swing arm suspension will suffer torque reactions from acceleration and braking that I did not want, especially on a truck with this much available torque. Out of curiosity I contacted them about it.
I was pleasantly surprised to find that they have more recently introduced a 4-link plus Panhard rod version, which by its nature eliminates the torque reactions. This is similar in type to the Kelderman, though a lot different in detail: they kept many of the clever features which made it a bolt on conversion, and they assured me they could do it to fit a 2WD dually. I grilled them a number of times on the phone about clearances, strengths, etc. I did my own engineering analysis on it. Their approach is not really a theoretical engineering oriented one, more a product of long experience building logging trailers and hundreds of air suspensions installed in emergency vehicles. They seem to know what works and what breaks. For the most part, each question I asked had an answer with reasoning and experience behind it. The shipping from Canada is expensive, so I figured I was probably stuck with it once ordered. In the end I decided it was close enough to what I had drawn for my own design to buy it as a starting place - I could always modify it if needed. So far, I have a couple of interference problems unique to the 2WD dually which I am confident will be resolved, I don't think I would change a thing with the design.
