Alloy
Well-known member
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.
pivoting frames and mounting campers
- Thread starter lehel1
- Start date
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.
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.
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
Yep, and IMO the way to go (I think all domestic 1-tons are fully boxed now...?) if the payload works out for you.
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.
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
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.
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.
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.
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
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.
This is how I have done it, and use currently with our custom camper.
Front saddle fab
Saddle resting on oak boards, and thru bolted to frame webbing.
Subframe is allowed to pivot up-down as needed via bushings/bolts
Rear pivot & bushing
Rear of frame notched, boxed and clearanced to accept rear pivoting subframe
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.
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
Do you have any pics of this setup?
I'm building a 3 point subframe. I would absolutely appreciate some measurements or diagrams if anyone has any. Mainly after plate size, thickness, rod size etc.
I do think spring mounts would be easier to fabricate, but after going through the pivoting frames and mounting campers thread I'm thinking I need a 3 point mount system. The truck I have is an international harvester mk4. It's an ex military unit designed and built in australia. These things were apparently renouned for their chassis flex, however build strong with a ladder frame so I highly doubt the chassis is going to fail like the fuso one did.
Any insights on this would be appreciated
I do think spring mounts would be easier to fabricate, but after going through the pivoting frames and mounting campers thread I'm thinking I need a 3 point mount system. The truck I have is an international harvester mk4. It's an ex military unit designed and built in australia. These things were apparently renouned for their chassis flex, however build strong with a ladder frame so I highly doubt the chassis is going to fail like the fuso one did.
Any insights on this would be appreciated
rruff
Explorer
There is a huge amount of twist there, just between the cab and bed... extreme.
I made a sort of 3-point using poly cab mounts from Energy Suspension.... just put the rear ones on the centerline so they pivot, and bridge across the frame rails to support them. They pivot easily when arranged that way. I'd suggest putting the "fixed" points spread wide in the front (which are also poly mounts) and the rest in the center. ES told me they were good for 800lb static load each, but I don't have that much weight on them.
I made a sort of 3-point using poly cab mounts from Energy Suspension.... just put the rear ones on the centerline so they pivot, and bridge across the frame rails to support them. They pivot easily when arranged that way. I'd suggest putting the "fixed" points spread wide in the front (which are also poly mounts) and the rest in the center. ES told me they were good for 800lb static load each, but I don't have that much weight on them.
Yeah it's a crazy amount, and those trays are directly mounted with u bolts, but the trays were designed to flex
They also made them in dump trucks so I'm thinking of trying to suss that out, problem is the trucks are very rare and little to no info online.
I'll have to look into your system, how many mounting points are there?
They also made them in dump trucks so I'm thinking of trying to suss that out, problem is the trucks are very rare and little to no info online.
I'll have to look into your system, how many mounting points are there?
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