Ram 5500, how much does that frame flex?

[dentedvw]

My buddy told me that he saw here somewhere a photo showing someone lifting a rear corner of their Ram 5500 with a forklift to demonstrate how little flex it has.
I am now at the point where I am designing and ready to build my subframe on my 5500, to mount my party rated camper box, but I am struggling with finding mounts to use for the 3 point system. I am beginning to wonder if it is truly necessary. My buddy said he saw that photo where a fella lifted the rear and found very little flex overall.
I feel that a 3 point mount is still probably ideal, though I am curious.
Does anyone remember that photo, and if so where to find it? I have done some digging, but have been unsuccessful.

 

[Darwin]

You will have go find the thread your buddy is talking about. Everything I have heard is that the 5500 actually flexes more due to the fact that it is an open C channel design vs a boxed frame like on the regular pick ups. If you don't plan to go off road much you might be able to get buy without a 3 point mount. Of course you could also consider a captive spring mount in the front, which is what I went with.

 

[dentedvw]

It flexes as much as you'd guess. Front wheels still planted. Right rear getting a bit light on the pavement. Insignificant amount of flex just behind the cab. Three point mount it is.

 

[billiebob]

You could do what semis do. 2 solid mounts at the firewall and 2 air ride mounts at the back. I hope your box has some flex designed in cuz everything flexes on the road.

 

[dentedvw]

It's going to flex as much as it's going to, I suppose.
Fairly standard three point mount system, only I used F450 spring mounts, as they are inexpensive, and easily purchased.
Hoping for best, in the end. Not an engineer. Just a dummy with a welder, and limited resources. The part that I worry about is the back wall, but since the original box truck steel frame is still in place back there, I think it's sort of sturdy? Planning to glue and screw an FRP panel in place. I imagine it will be the first thing to fail if things go pear shaped and it flexes a lot. Not much money lost if so. Just time, mainly. Speaking of time, i best get to it, it's a day off work. Ha ha!