Cabover struts?

Farmerjon wrote:
SoCalDesertRider
Welcome back.

Thanks, Farmerjon! :)

Butch50 wrote:
Off Topic:

SoCalDesertRider, where have you been I thought we had lost you from the forum?

Hi Butch! I was on hiatus, got too busy with large jobs to spend time on the forum. Feels good to be back. :)

Rooney,
You're talking about front TC bed bumpers. These are Lance camper guides; There are several on here that fabbed up much better ones than these (do a search:Camper guides) or even used 2x4's between the fender well and the TC walls. It takes a lot of stress off the camper frame and tie-downs.






Right now I'm working on using a strap to hold the TC from sliding off the back. I also use the hand-tight only on tie-downs.
jefe

rooney77 wrote:
When I took my camper out for the first time I felt like the camper was moving to much. A rocking motion more than anything. I had tightened the turnbuckles to where I felt they should be...hand tight then a few more turns. So I'm wondering would some sort of cabover to cab brace help the camper feel more like it's "one with the truck"?

edit: Guess I should mention that I have firestone airbags and the tie down system is happijac.


Sorry I've been asking so many questions. I'm just new to the whole RV thing in general and I haven't a clue what to expect. And I try to search for solutions before posting.

Leaf helpers (Super Springs) I use for load.

Air bags, I use for ride. (bags were designed for ride)

Sway bars are for sway (sideways rock 'n roll)

It sounds like you need a good set of rear sway bars

If you use the bags for load, you will get more sway & bounce.

Lynnsr

SoCaldesertrider has a point. The stops for the overloads are not what I am talking about. I am talking the rubber bumpstops on the spring shackle that stops movement in the spring so the differential assembly does not hit the frame.
OP: Did you know what the weight of the camper is? It could be over the rating of the Happijac tie downs.
Many people with large or heavier campers go with Tork Lifts.

I checked the COG and it's right over the axle. Lot of good indo on what's what under the truck. It should be added that the bump stops are generally removed when air bags are installed. On this year range dodge at least. Thats the bump stop, not the overloads.

As for bed flexing, if the bed is twisting that would be more of a sway type sensation. The frame would have to be bending in half to replicate what I'm feeling with my setup.

My cabover bounces quite a bit when looking at it from the drivers seat going down the road (23' long bed crew cab). But my impression is that it is the truck frame that is flexing rather than the cabover of the camper. Ford had a video a while back showing their truck and a competitors going down a railroad track, with the camera looking back at the bed. It was amazing how much the beds were flexing (of course Ford was flexing less, hence their video).

It seems to me that a cabover strut takes the forces flexing the bed and transfers them to the camper structure, reducing truck flex but increasing internal flexing of the camper. With a wood frame this might not be too bad, but would lead to stress cracking of an aluminum frame. The steel of the frame handles flexing better than aluminum.

This is different from porpoising, in which the whole truck is bouncing as a unit - air bags, upgraded shocks and Torqlifts have helped reduce that.

Also bump stops (the last resort to keep the wheel from hitting the wheel well) are different from the helper springs engager stops which are what is replaced with a Torqlift or DIY.

I used to use the overhead struts but that was 30 years ago and campers and trucks were different. I do keep the tires aired up and use overload bumpers (DIY).
On our last trip (we got home last week) we travelled from Mo to GA and NC and were on some roads that had pretty bad joints that set us up for porpoising, switching lanes helped. Before we put the overload bumpers on those joints bothered us a lot more.

SoCalDesertRider
Welcome back.

Off Topic:

SoCalDesertRider, where have you been I thought we had lost you from the forum?

enblethen wrote:
I don't think you want the rig sitting on the bump stops. This would effectively defeat the purpose of the springs.

I think there may be a confusion here about which bump stops are being discussed. On a truck with overload springs, there are 2 types of bump stops in the rear suspension.

One set of bump stops (4) is for the upper overload springs, usually 2 on each side of the frame, positioned above the ends of the springs. These give the overloads something to act against to help support the truck.

On most stock trucks, the factory has positioned the overload bump stops up too high on the frame to be effective, until the truck is so grossly overloaded that it is almost at maximum suspension compression height. This is why most truck camper folks here use Stable Loads, or other home-made solutions, to effectively drop the overload spring bump stops down lower, which causes the overloads to come into play sooner, before the truck is dragging it's bumper on the ground, so to speak. :)

The other set of bump stops (2) is for the axle, on the bottom of the frame rail directly above the axle tube. These limit the axle from hitting the bottom of the frame at full suspension compression.

It is highly desirable to have the loaded truck ride on the overload spring bump stops.

It is never a good idea to have any vehicle riding on the axle bump stops.

I agree with all the others so far who have said to lower the air bag pressure and install Stable Load bump stop extensions to let the overloads do their job sooner in the game.

As for the rear tire pressure, 65 psi is enough for your dually to support the camper just fine. I run my dually rears at 65 psi and have 8000 lbs rear axle weight daily. No problems with insufficient tire pressure. If it were a single rear wheel truck, then definitely you would want to run them at max 80 psi, as I do with my other, single wheel F350.

I've never owned a Lance, which is the only camper brand I know of that recommends using cab struts and actually designs their campers to be used with them. If I owned a Lance, I would likely use the cab struts. Any other brand, I wouldn't, and havent. They do seem like a very good idea, for those campers that are built such that the struts won't stress and crack the camper overcab framing.

One other consideration. I see from your picture that the rear axle on your truck is quite far forward, due to the short MegaCab bed length. It is possible the campers front/rear center of gravity point may be positioned reward of the rear axle's center line. This can cause the camper's weight to unload the front axle, which can aggravate porpoising, rocking and steering/handling of the truck. You should seek to load weight of personal items as far forward as possible in the camper, or in the rear seat of the cab, if you can. Keep your waste tank(s) empty too, as they are usually at the rear of the camper.