pivoting frames and mounting campers

Alloy

Well-known member
I don't think notching any 'beam' would be a good thing. It's always best to keep the top and bottom cord undisturbed. Also, it's never good to weld across the cord, along the cord is fine. Any change in the thickness of the cord is a stress riser and will start cracks and break. The longitudinal runners are the primary beam and carry all the load. It's better to leave them undisturbed as possible.

This is mild steel and the loading / strength is low. If it was aluminum or heat treated it is still possible but more precautions (doublers/gussets) are needed.
 

Bama67

Active member
Are the newest pickup trucks with a fully boxed frame; like say a 2022 F350, NOT a cab and chassis truck, stiff enough to avoid the headache of a pivoting frame?
I had a 2018 F250 with heavy steel front and rear bumpers and it seemed like it didn't flex any real appreciable amount.
I sold that truck during peak Covid and went back to a 2007 F250. This truck flexes enough that when I cross it up I can barely open the doors. lol
sorry if this has been answered.
 

rruff

Explorer
Are the newest pickup trucks with a fully boxed frame; like say a 2022 F350, NOT a cab and chassis truck, stiff enough to avoid the headache of a pivoting frame?

Yep, and IMO the way to go (I think all domestic 1-tons are fully boxed now...?) if the payload works out for you.
 

Zuber

Active member
I just toured Earth Cruiser and looked at a new Terra Nova, built on a 1-ton Cab-Chassis RAM. They are just mounting the camper frame directly to the truck frame. They only have poly spacers to cut some of the vibrations.

On my 2500 RAM, I mounted directly to the frame also. Crossed up and fully loaded there was no measurable flex.
 

Alloy

Well-known member
Are the newest pickup trucks with a fully boxed frame; like say a 2022 F350, NOT a cab and chassis truck, stiff enough to avoid the headache of a pivoting frame?
I had a 2018 F250 with heavy steel front and rear bumpers and it seemed like it didn't flex any real appreciable amount.
I sold that truck during peak Covid and went back to a 2007 F250. This truck flexes enough that when I cross it up I can barely open the doors. lol
sorry if this has been answered.

There's no perfect answer.
- How much weight
- How severe is the road
- For how long/often
- How is the box made
 

GoinBoardin

Observer
My '96 F150 will jam up the doors. I've had to crawl out the window when stuck in such a situation. Was more an issue with two open diffs, but the old trucks are not great in regards to torsion.

I have had my camper on a 3 point mount, front pivot with shocks, for several years now. Maybe 6 years, and 80k miles. Extended cab short box Ford with a heavily modified FWC Fleet, as a flatbed. I went front pivot bc I read on here that that's ideal. After my experience, I'm very interested in switching to a rear pivot and seeing the difference. My camper has a short cabover, and by design is heavier in the front (batteries, electronics, water, storage, all up front). I think having the pivot on the heavy side may be a mistake. I have about a 4" gap between the bottom of the camper cabover and the top of the truck cab and have had contact between the two. But more of an issue for me is the sway or sort of rocking the camper puts into the truck when hitting alternating left right dips. Prior to the shocks it was not good, the shocks make it tolerable. Off camber situations it feels like the camper tips downhill more than it should, certainly more than it did when I had it hard mounted. I think this is due to the pivot sitting under the heavy end.
 

IdaSHO

IDACAMPER
Ill always recommend a rear pivot for a few reasons.

Biggest one is the allowable space between cab and camper can be much less with a rear pivot. This helps bring the overall COG as well as height down.

Second one is with regard to weight shifts as the truck rocks left-right. A well designed camper will have a forward weight bias. So assuming its designed correctly, then yes, a rear pivot will be considerably more stable as most of the camper weight is supported by the fixed front mounts. Still, with a rear pivot there is still a great deal of weight on the rear, so managing that “tossed weight” during rocking is crucial. Properly located shocks to slow/dampen that movement helps tremendously.
 

GoinBoardin

Observer
My camper is pretty light at about 1200# fully loaded, and I would estimate that as 800# forward, 400# rear, based on my ability to manipulate the rear end but not the front. Water and batteries are not centered up front but on opposite sides, near the edges: not ideal.

My truck frame ended up cracking at the rear axle shock clearance points, both sides, though a few years apart. I'm not sure if it's from the camper inducing extra twist into the frame as it rocks or simply a product of rough roads, age (28 years), and a lot of miles (355,000). Probably both. On the right road the camper really starts tossing, and while the shocks work to damp the motion the rear of the truck frame sees a good deal of torque from it. I think I'll rearrange for a rear pivot and see how it works. This truck is probably nearing retirement but it will be a good test nonetheless.
 

IdaSHO

IDACAMPER
A half ton Ford at that age and mileage, its likely a combination of reasons why it failed.

Any photos of the current truck and camper?
 

IdaSHO

IDACAMPER
My camper is pretty light at about 1200# fully loaded, and I would estimate that as 800# forward, 400# rear, based on my ability to manipulate the rear end but not the front. Water and batteries are not centered up front but on opposite sides, near the edges: not ideal.

My truck frame ended up cracking at the rear axle shock clearance points, both sides, though a few years apart. I'm not sure if it's from the camper inducing extra twist into the frame as it rocks or simply a product of rough roads, age (28 years), and a lot of miles (355,000). Probably both. On the right road the camper really starts tossing, and while the shocks work to damp the motion the rear of the truck frame sees a good deal of torque from it. I think I'll rearrange for a rear pivot and see how it works. This truck is probably nearing retirement but it will be a good test nonetheless.

Did some digging and found your old thread.

From the photos posted, I doubt the camper or method of mounting was directly responsible.
It likely age, mileage, and long term weight and weight transfer (side to side) were all contributing factors.

Though I must point out as a heads up... with regards to the rear (fixed) point.
While it looks like it may have worked okay, this is NOT an accepted design or method.

The "fixed" points must be able to articulate up and down in order to see full benefit of the pivoting end.
In its current configuration in the photo any pivoting requires the steel to deflect/bend, which will work harden over time and eventually fail.

20180722_090413-jpg.461860



This is how I have done it, and use currently with our custom camper.

44093839072_7ecf40dc2b_b.jpg



Front saddle fab
32382391138_9e7b882d6f_b.jpg


Saddle resting on oak boards, and thru bolted to frame webbing.
Subframe is allowed to pivot up-down as needed via bushings/bolts
43423796494_7df48a1e58_b.jpg


Rear pivot & bushing
47755738182_a0e35b59a0_c.jpg


Rear of frame notched, boxed and clearanced to accept rear pivoting subframe
45530755624_fb9f809292_b.jpg


42334500620_dd3790cfc7_b.jpg
 

GoinBoardin

Observer
So I swapped to a rear pivot. Huge difference. Camper moves around way less. Doesn't flop to the downhill side so hard off camber. But still keeps the torque out of the camper. I don't have shocks installed and don't think I will this time.

I did it quick and dirty with another rigid fixed mount to test, but in a way I can update it in the future with two poly bushings to match what IdaSho suggested above. I understand the reasoning after thinking on it. I suspect I got away with it bc the 3/16" angle I used was quite flexible.
 

ExpoMike

Well-known member
So I swapped to a rear pivot. Huge difference. Camper moves around way less. Doesn't flop to the downhill side so hard off camber. But still keeps the torque out of the camper. I don't have shocks installed and don't think I will this time.

I did it quick and dirty with another rigid fixed mount to test, but in a way I can update it in the future with two poly bushings to match what IdaSho suggested above. I understand the reasoning after thinking on it. I suspect I got away with it bc the 3/16" angle I used was quite flexible.

Do you have any pics of this setup?
 

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