Printable Version of Topic

Click here to view this topic in its original format

Truck Camper Forum _ Support Equipment _ Too much rocking back and forth when hitting bumps

Posted by: Fandini Oct 1 2017, 12:11 PM

Alrighty. New to the site and 2 weeks into the truck camper scene. Had a great experience with the dealer who was honest and guided me into the right directions for things and add on to the truck and did not try to sell me more than I might need. I have a 2017 Ram 3500 4x4 Crew Cab long bed single rear wheel with an Artic Fox 990 camper and firestone airbags added. I'm using Torklift Fastguns tie downs. I'm getting a lot of rocking of the camper in a front to back direction when going over bumps down the road and if the road is really bumpy the over cab portion of the camper almost seems to hit the top of the cab. The fast guns were set and labeled by the dealer and I feel they know what they're doing. Still...... I feel like I'm on the end of a bungee cord when driving getting jerked front to back. When going off road, beach driving mostly, I'm worried something may get damaged. Can somebody give me some advice on stopping this excessive rocking chair style of motion of the camper?
Thanks
Bill

Posted by: Chief 2 Oct 2 2017, 05:49 AM

It is called porposing. What pressure do you have your bags set at? To high could be part of the problem. On my Lance I have the front struts that are a huge help with eliminating it. I believe that Lance is the only company that uses them though. Sorry I can't give you anymore advice on the problem.

Posted by: Fandini Oct 2 2017, 09:55 PM

QUOTE(Chief 2 @ Oct 2 2017, 05:49 AM)
It is called porposing. What pressure do you have your bags set at? To high could be part of the problem. On my Lance I have the front struts that are a huge help with eliminating it. I believe that Lance is the only company that uses them though. Sorry I can't give you anymore advice on the problem.
*



I started with 50 lbs in the air bags but pumped them up to about 70 to stiffen the rear to counteract body roll. I don’t really think there was any difference in the camper unit porposing between the 2 different air bag settings but I can only try it at 50 lbs again and see. I will be adding a Helwig sway bar for the body roll later on.
Thanks
Bill

Posted by: SidecarFlip Oct 4 2017, 09:36 PM

QUOTE(Fandini @ Oct 2 2017, 09:55 PM)
I started with 50 lbs in the air bags but pumped them up to about 70 to stiffen the rear to counteract body roll. I don’t really think there was any difference in the camper unit porposing between the 2 different air bag settings but I can only try it at 50 lbs again and see. I will be adding a Helwig sway bar for the body roll later on.
Thanks
Bill
*



When I had my Lance 918 (which was a tank), I ran my bags at 40 pounds maximum and I ran Rancho RS 9000 shocks in the front and rear with a factory sway bars front and rear.. I've since switched campers and shocks I have a lighter camper now (Palomino SS1500) which weighs about 2500 wet. I run 30 in the rear bags maximum. I went to SkyJacker Monotube Black Max shocks. You never want to run a pressurized nitrogen shock on a truck, always a conventional hydraulic dampened shock, preferrably with strong rebound damping.

Porposing is caused by a couple things, The Cg can be too far back which can be corrected by loading the unit with your heavier gear farther forward (so long as the camper is loaded as far forward as possible, that is, not having a unit for an 8 foot box loaded in a 6.5 foot box (that puts the Cg back and causes handling issues, Too much air in the bags causing the weight to transfer to the front axle abruptly on throttle changes or a swoopy road and having too much air in the bags causing the truck to sit un-level.

You only want enough air in the bags to level the truck and no more.

Even when I pull my tri axle gooseneck overloaded with round hay bales, I never run over 60 psi in the bags, only enough to level the truck and no more.

One, I think you have too much air in your bags.
Two, your front shocks (and possible rear shocks) need changed to a conventional hydraulic mono tube shock, Rancho, SkyJacker or whatever you prefer but no gas charged shocks. Only conventional
Three. Your Cg May be too far back and if it is, load the front of the camper with heavier stuff and keep your black and grey tanks as close to empty as possible.

I think a shock replacement and lowering your pressure will do the trick.

Posted by: Freespool Dec 9 2017, 12:39 PM

I recently read an article provided by Truck Camper Magazine where they were testing front struts on a Lance. Back in the day these were commonly used but nowadays not so much. Lance is the only builder still endorsing them according to the article. I think the above tips will be your best remedy but the addition of the struts may provide a little more help. The article is interesting and provides both the pro's and con's of the product. The overall opinion of the product was mostly positive. Good luck

Posted by: emcvay Nov 2 2018, 07:26 AM

I run the 990 on an F350 SRW and had the same issue. The fix? For the most part it was Rancho 9000's. The shocks are adjustable and I set the rears to 9 (hardest) and fronts to 7 and the porpoising stops for the most part.

Also added upper and lower stable loads which all but made the air bags an after thought now and added a Hellwig BigWig rear sway bar.

Lastly, don't forget tires! The 990 is a heavy beast at nearly 5000lbs when fully loaded so you will need good tires. I run the Toyo's which are rated at 4080lbs per tire

Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)