http://www.samsclub.com/sams/bf-good....ip?navAction=

These are the tires I went with. They're very quiet and have a smooth ride. They're supposed to be a newer design for mostly highway with a little off road in mind. Being a truck driver for 22 years I know that new tires can be squirmy for a while but I don't really think that's happening here.

 

I can't say the tires were bad, but in my application it didn't work out. I guess there is a good reason for Ford using closed shoulder tires on the 19.5" equipped 450's and 550's.

 

I used the kit you have. I sold it at a loss on ebay when I realized it caused more sway than without. I bought a different kit. I could have just bought new bracketry but the cost was high so not worth it to me.
I run a mud tire, e load range. 3750# rating I believe. Pumped up to 80psi. With a top heavy slide in camper. I would love some 19.5" wheels but thats not the way to fix Phil's problem.

 

Yeah I've thought about trying the RAS add ons,but I liked the idea of airbags being adjustable.

 

Thats your call on the RAS. I ripped those off and gave them to a friend. They rode like poop when empty and made the ride height higher.

 

Those 19.5 tires are a different critter!

 

One more thought on those inboard mounted air bags:
If part of the truck weight is moved from the original spring location inboard, the axle housing is now bent in a more extreme manner than originally designed by Ford. The spring mounts are located as close to the tires as is practical to minimize the arch in the axle housing. The more arch, the more the axle is angled in the inner and outer bearings and seals and this can affect the bearings. An air bag manufacturer who chooses to move the weight distribution inside the spring mount location is making a decision which can affect the handling and longevity of the truck. Now you have a decision to make!
Larry

 

I struck out on the tires but am still trying. I would try playing with how much air psi you put into the airbags. 45 psi with that tongue weight seems kinda high. My understanding is, the air bags assist but don't eliminate the stock suspension. I have a modified air bag suspension under my truck and I run 25psi with a 900lb tounge weight. With the same rear suspension folks with a heavy 5th wheel and >3000lb pin weight run 40 psi.

 

Your weights look good on your axles. I agree with the post about running with the minimum air pressure so the bags are doing nothing (basically taking them out of the equation) and see if the problem persist. My bags are mounted inboard of the frame and though I don't pull a trailer that big I use a slide in camper and tow a trailer with a vehicle on it and have noticed no increased sway due to this configuration. I have replaced my sway bar bushings with urethane. Larry, as far your statement about axle flex, if your axle flexes (your statement "axle housing is now bent") you are way over loaded. That housing should not be bending no matter where you do or do not have bags. If it bends you are way over loaded. Physics say that the wider the support the more stable a load will be, so adding addition capacity with bags should only help, no matter where they are placed along the axis.

The one thing that just came to mind typing this that no one has mentioned is that your truck is an 1999. If your spring bushings are bad (that old, many miles and towing abuse, I would bet they are) when you relieve some of the weight from them with the bags this unloads the springs and bushings which will allow the axle to float through the free play in the bushings. This would definitely give you that squirmy feeling. I have seen it many times through the years as rubber parts start to deteriorate. Bags, no matter where they are located, should not cause your issue. If you change nothing but the bag location I would be willing to bet it will not fix your problem. If you want to change something that is guaranteed to make things better I would replace the rear spring bushings with urethane. Like is constantly repeated on this forum about engine mods, make sure everything is right before you start modifying. The same holds true to suspension components.

Good luck and keep us informed.

 

My air bags were below the frame - not the best place. I ran them 50psi or less. The best sway reducer for me which also added load carrying ability was extended bump stops for the upper overload spring, and torklift wedges for the lower overload. These allowed the entire springpack to be used immediately, and were located at the best place to reduce sway. I'd recommend the torklift bump stops and wedges first, air bags second. I had such a heavy load with the camper that 19.5" tires were also needed - a great sway reducer, but it doesnt sound like you need those.

 

The lower Torklift Stableloads with quick disconnects were the best mod ive done for weight carrying help.

 

Dave, good comments all the way around. Perceptive idea about the bushings as well. I think I will put bushings on my wish list for my 99 as well.

 

Guys I appreciate the advice. @Dave spring bushings and the bags taking load off of the springs seems like a possibility. I haven't had time to check, but like I said in the OP it's not like "sway". It has more of a something is loose or off kinda feel. It's hard to describe. I'll be sure to update when I check it out further...Phil

 

How much play do you have in your steering box?

 

If the spring bushing are bad that would allow the axle to shift for and aft (possibly one side more than the other) which in essence would make the rear axle a steer axle. That would definitely make it feel "loose or kinda off". With the fact that it seemed fine before the bags and now with the addition of the bags your sway probably actually decreased but you picked up axle shift. Traded one demon for another. You gotta love this stuff.

Good luck.