1/2 ton or 3/4 ton?

I've had a similar issue with this myself when I first started towing with my wagon. I had no idea what I was getting into at the time. Based on brochure weights and what I thought I was packing, I estimated I was towing 4-5k lbs in a light weight 26' trailer (bumper to ball). I didn't understand the effects the length of the trailer when impacted by wind or other vehicles would have on my stability before hand. Test tows on back roads were fine but the first camping trip had us on the highway immediately and I was struggling to keep it in my lane. I tightened up the friction sway control bar and that helped considerably and I was able to make the trip but I was not happy with how it behaved. To reduce the side to side motions the bar was so tight I could feel that it was not letting me just travel straight down the road as well, I was constantly making small corrections. It was easier to drive around curves and maneuver in traffic, it just didn't like going straight and still was impacted by large vehicles to a noticeable degree. I then upgraded my sway control to the Reese Dual Cam system, that made a HUGE difference. I then felt like it tracked straight down the road, even large semi's passing me rarely moved me around unless we both were hugging the center line of the interstate lanes. I still had some issues on windy days. A couple of years later I upgraded to a performance summer tires designed for SUV's. That improved things even more and we had a really enjoyable drive from MI down to the Smokey Mountains last year with no issues. One very windy section had me slowing down to 60-65, other than that we cruised at 65 the entire time. Since then I've taken a fairly long trip with a borrowed F350 supercab long box and a shorter trip with my newly acquired 2500 Suburban. Those both seem better yet. Very stable.

To compare my experience with your situation, I see some differences. First, I never had stability issues related to speed other than the fact that if the wind was blowing me around or a semi was blowing me around, going slower made it easier to handle. On back roads up to 60 mph with no traffic passing me (in the same direction) I felt very stable other than the issue with it not wanting to track perfectly straight, that was more annoying than worrisome. If with no wind and no other vehicle around you feel unstable over 55, then something seems wrong to me. It might be helpful to get your vehicle and vehicle trailer combination weighed. With this you can determine if you are overweight, what your tongue weight is, if any particular axles are overloaded and if your W/D hitch is set up correctly. If your tongue weight is low that can lead to instability at higher speeds, definitely something I would want to understand if I were you. At one point I took the time to weight my set-up and found that my trailer was much heavier than I thought (nearly 5600 lbs compared to my 4-5k lb estimate) and my tongue weight was 970 lbs, 17%. Much higher than the 10-15% recommended. For RV's many suggest getting down in the 10-12 range can be less stable, most shoot for 13-15%.

There is another forum member on here that tows a longer trailer than yours that is around 6500 lbs and he feels he is at the absolute limit of his Expedition. His rear axle is nearly at its limit. If you weighed your rig you might find you are overloaded and it may make sense to upgrade even if your issues can be corrected with the Expedition.

Another difference between the options I had versus you is my wheel/tire combination happens to be the same size as some older Porsche SUV's and I had a nice XL high performance tire option to go with which gave me a much more solid sidewall in my tire with tread that had next to zero squirm. A huge difference. For you, you might find a LT truck tire, versus a P metric tire, would be beneficial for stability.

You didn't say what kind of W/D hitch you had or the type of sway control. You might find significant improvements there as well like I did. First I would weigh everything and see what your needs are as far as addressing potential tongue weight issues and the towing and weight capacity needs of your tow vehicle. I think it is necessary information to have regardless if you keep your Expedition or buy something different. You do not want to buy another tow vehicle and end up in the same situation.

As for 2500HD trucks being gas hogs. The newer ones with the 6-speeds transmissions are much more fuel efficient than the older ones with the 4-speeds. They are probably as fuel efficient as your Expedition. New body style pick-ups starting in 2007 model year have 6-speeds (2007 Classics are the old style body and 4-speeds). 2008 was the first year for 2500 Suburbans to have the 6-speeds as the first year of the new body style, 2007, still had the 4-speed trans.

bryoderwls wrote:
The motion is side to side and happens when large vehicles pass on the interstate, going down hills and any time I get over 55 mph. The only reason I've been told about the air suspension is because it is an "air bag suspension" and works like a balloon. The air moves and therefore causes the sway.
The Expedition only has 69000 on it. One garage I went to about it said, "I get this concern about 10-15 times a year. Ford knows it is an issue and hasn't done anything to fix it. The options are to replace it with a different system for about $2,000 or trade it in."

The way you describe your towing condition above you are experiencing trailer sway. That is not "floating". You can correct trailer sway by utilizing an anti sway hitch design. The 2 common manufacturers are Reese Dual Cam hitch and Equal-i-zer Anti Sway hitch. Do a search and read up on those. They should be in the $1,000+ or - range installed. There is also the Hensley anti sway hitch which is considered the best available but it is in the $3,000 range. Your sway problem is 90-95% curable with either of the common hitches I've mentioned.

olddesertrider

The motion is side to side and happens when large vehicles pass on the interstate, going down hills and any time I get over 55 mph. The only reason I've been told about the air suspension is because it is an "air bag suspension" and works like a balloon. The air moves and therefore causes the sway.
The Expedition only has 69000 on it. One garage I went to about it said, "I get this concern about 10-15 times a year. Ford knows it is an issue and hasn't done anything to fix it. The options are to replace it with a different system for about $2,000 or trade it in."

I consider "floating" and up or down motion and "tail wagging the dog" a more side to side issue. Do you have issues at times, due to wind or other passing vehicles, where it doesn't want to stay in the middle of the lane and you are constantly correcting?

Considering the weight of the trailer, I'm sure you will be happier with 3/4 ton vehicle. A longer wheelbase 1/2 ton with the appropriate payload (which is not always easy to find) would likely be an improvement as well. As for your Expedition, I'm not sure why the air suspension would be the issue, it is just a spring that supports the weight vertically. The shocks control the motion vertically. The independent rear suspension, if in good condition, should locate the rear wheels side to side very well. I have heard of issues with the Expeditions where the rear suspension bushings wear out and get sloppy, another potential issue. How many miles are on it?

By "floating down the road," I mean that it feels like the tail wagging the dog.
As far as weight Distribution goes, I don't know how to adjust it. We have adjusted the sway bars to put more weight on the hitch, loaded the front of the trailer, etc. It has the same feeling when pulling a small trailer with a mower on it. So far, I haven't found anyone, mechanic or RV guy, that has been able to help me. Everyone I've had it to says it is typical of that kind of air bag suspension. I'm pulling my hair out trying to get this straightened out when I have yet to find anyone who can physically help me.
I was also told that my trailer could have a bent axle. While in getting some other work done, they said it was fine.
I did pull it with a Chevy 2500 and if it masked the feeling, then fine. It rode beautifully and pulled like it wasn't there. I appreciate all of the suggestions and help, but I am clueless as to how to do the WD adjustments.

Or your shocks may be worn out. My new to me 2003 2500 Suburban floats more than my 1996 Woody wagon with Bilstein shocks. I'll be buying new Bilstein shocks for the Suburban next spring. In all other respects it feels superior when towing to the wagon but it floats and bounces. It does somewhat without the trailer as well. Shocks don't last forever.

Perhaps it would help if you better described what you mean by "floating down the road".

dodge guy wrote:
The air suspension will not cause the float feeling you describe. most likely it is because of an improperly setup WD hitch. a lot of people describe the feeling you have and just go out and get a bigger truck and use the same poorly setup WD hitch that is now masked by the heavier truck. read up on how to properly adjust a WD hitch with the air suspension (I believe Ford even has a page or 2 in the owners manual on how to do this!), then be sure you have the proper tongue weight and properly sized WD bars, too heavy a bar can cause the same issue because it will remove too much weight from the rear axle. then take it out and see how much better it handles.

Personally, I think this is great advice and if it was me, I would give this a try first. Especially for the length/weight you are towing. I used a similar TV (2007 1500 Suburban LTZ/4.10/6.0L with air ride), towing a bit longer TT, and didn't experience any float. Why waste any money if you don't have to.

The air suspension will not cause the float feeling you describe. most likely it is because of an improperly setup WD hitch. a lot of people describe the feeling you have and just go out and get a bigger truck and use the same poorly setup WD hitch that is now masked by the heavier truck. read up on how to properly adjust a WD hitch with the air suspension (I believe Ford even has a page or 2 in the owners manual on how to do this!), then be sure you have the proper tongue weight and properly sized WD bars, too heavy a bar can cause the same issue because it will remove too much weight from the rear axle. then take it out and see how much better it handles.

Buy a 1 ton GM truck and get it over with. You won't regret it.
Good luck.

Is it more important it fit in the garage or safely tow the trailer?