When loaded down you may be forcing the truck onto the overload springs.
If they weren't meant to be used, what's the point of having them?
"Overload springs" is just as big a misnomer as "1/2 ton truck." The springs aren't really there so you can overload (i.e. put too much weight in) the truck.
2002 Chevy 3500 DRW 8.1L/Allison
2000 Palomino B1500
...and the reason why I need a DRW to haul a Palomino:
2004 United 7x14 tandem axle enclosed toy trailer
2011 PJ 8x20 7-ton deckover equipment trailer
Your truck does not have to ride on the overload spring to carry any additional weight, only once it gets to a certain point of load will your truck sag enough for these to engage. Once you are riding on the overload spring your ride will suffer.
I also disagree with this statement if I'm reading it correctly. I have never put a full size camper onto a stock truck and not had the overloads come immediately into contact. AirLiftCompany seems to indicate that's not the norm. I think it is. Perhaps they were not thinking of Camper-load when they said it -- but this IS the camper forum.
Who out there are running a full-size cabover camper on a stock truck and have gaps under your overload springs? Maybe it's a marque thing.
Thanks for all your help. So, now I am really confused. A lot of the recommendations on this forum are to switch out the stock shocks, two suspension shops have told me to get rid of the Timbrens and modify the leafs. One shop says, add two leafs the other says one. As a matter of fact one of the shops told me that the Timbrens tend to split and cut the rear break hoses. So now I am also worried that on a long trip I could loose my brakes. Has anyone heard of this happening on their Timbrens? What I was thinking of doing before the two suspension shops was to switch-out the stock shocks with Rancho shocks and my ride remote and if that didn't do the trick to add Super Springs.
2008 Ford F350 dually
6.4 L Diesel
2010 Eagle Cap 1160
I don't have a T.C. but I suffered the same problem with my fiver. I had the timbrens on it and though they worked good when loaded they gave me a harsh bounce when I hit a big bump and here in Calif. there are a lot of big bumps on our crappy roads so I took them off and just run on my over loads and no more harsh bumps. Like others say it could be the timbrens on the kind of load you have.
I had just air bags at first and had lots of bounce and sway. My truck doesn't have overload springs. My ride improved dramatically, becoming much more stable after I put on Rancho 9000s. The remote adjust for them would be a nice luxury, but it takes about 60 seconds to adjust them by hand. I subsequently installed a sway bar, which reduced the sway around corners about 20 percent more.
2010 Ford F-250 4X4 Diesel with 2009 Lance 845
Rancho RS9000XL Shocks
Hellwig Bigwig Sway Bar
You are getting much more valuable advice from fellow TC'ers than you will get from a suspension shop or an air bag company.
I suggest an incremental approach which can save money and helps you understand how each component affects the ride quality.
The common thread is to start with new shocks. I chose Rancho 9000.You need new shocks no matter what anyway.
Then install Torklift Stableloads. They are the most low cost suspension option with the greatest effect, providing you still have the factory overloads. You can install them in your driveway in less than an hour.
You will probably not need the timbrens at this point.
Try it this way for a few trips before decidng about airbags. Your F350 may handle it without them.
One other detail to keep track of is your tire pressure.