Stupid Question About Rear End Seperation

[Swrider]

Ok now before u all go off the rails at me, remember that the title of this post started with the word "stupid".
Right then.
The question.
If i have rear end seperation, one how can one tell without doing extensive gutting/removal of various things.
Second, since i drove this trailer home a good 30miles, and previous owner drove it a good 50miles, how worried should i be about towing it around???
I'll leave some pictures here.
Thanks everyone.

[Belegedhel]

We are a disciplined, mature community--nobody goes off the rails unless you mention tow vehicles, the merits of weight distribution, or politics in general!

Anyway... To your question... The easiest way to tell if you have rear end separation is to step up on the rear bumper and bounce up and down on it (gently) and observe where the body meets the frame rails. If you have no separation, there should not be any noticeable difference in movement. If you have separation, the bumper will bounce up and down independent (to varying degrees) of the body.

The pictures you posted show a lot of damage--not sure if it is due to rear end separation, or somethign else. The big dent in the lower rear segment might be the result of a young bison charging at its own reflection, or it could be "oilcanning" (buckling of the shell) due to compression. This is not a usual symptom of rear end separation (but never say "never"), it looks more like something you would get if you drove the trailer through a deep gutter and up a steep driveway, and the rear of the frame bottomed out, and even resulted in a permanent bend to the frame rails. This you could check with a long straight-edge. You might also look under the bumper to see fi there is obvious evidence that the bumper has been dragged.

It also looks like someone has already drilled out a bunch of rivets, and then slapped the trim back in place (either that, or all those rivets have been sheared).

Can you tow it? Well, sure, so far it hasn't fallen apart on the road, but trailers with rear end separation don't usually fall apart. What they do, is suffer even more damage as the shell and frame move intependent of one another, and meet in the middle like a jack-hammer. So if you want to minimize further damage to the rear of the trailer, I would not plan any road trips.

Good luck!

[uncle_bob]

Hi

Like it or not, the shell (and the floor and the frame) all are part of the "structure" of the AS. Working together they keep it solid and functional as you bump down the road. Degrade any one of them and you have weakened the whole. A weaker trailer flexes more and that can easily create new issues.

Best to repair any significant damage or rot sooner rather than later ....

Bob

[Swrider]

Thanks for the comments guys.
So no big travel plans on this trailer, and actually the purpose of it will be to turn it into an extended living area for a house we are building. The only movement it will see is if i need to take it somewhere in town for certain repairs. But other than that it will sit on the lot for the next year or two.
So not too concerned with the seperation issue so long as i can patch it up and prevent critters and the elements to do further damage.

[guskmg]

Rearend separation (“sag”) occurs when the floor and the frame separate. It is a common on all aluminum body trailers. The longer the frame the more likely it will happen. I have seen it on a 23 footer. The separation is caused by the frame being overloaded in either up, down or both directions. The failure is evidentced by lower edge rear corner panel crumpling or rivets being pulled down vertically though the aluminum skin at the bottom, not sheared. It happens with bucked rivets as well as Olympic. The rear trunk door lower frame can also sag causing the door to open. Often, all you notice is the lower wrap around trim separating from the skin where it is caulked. The two main causes are overloading the frame, and a floor weaken from wood rot. That defeats the monocoque feature of the aluminum shell, no matter where it occurs because that is the design criteria for strenght. There are several ways to repair the damage. The rear corner segments need to be removed. If they are not damaged to the point of noticability when reinstalled with trim they can be reused, The obvious next step is to reinforce the lower rear cross frame and the vertical false ribs runing up to, but not attached to the horizontal middle beltline shell frame. This has been done using 4”or 5” steel 90 degree brackets. Long self tapping screws that go al the way through the rear frame are often used. Bolts, sometimes used, would be better. I have seen a heavy piece of angle used from side to side across the upper rear floor. There are some other reinforcements out there. That depends on the shop. Idealy, if you clamp the “C” channel to a fabricated curved frame member below the floor all aroung the perimiter that would be even better. Colin Hyde, who does restorations and repair in Plattsburg, NY, has vast experience in reparing rear end separation. Call or email. (518) 578-7772 <colin@colinhydetrailerrestorations.com> He is busy ,so be patient.
One caveat, in my particular case with two trailers and three occurances, vertical over load is a no no! I would be careful even with the approved Flamma bike rack. No traler hitches or genny platforms.
Nothing! Raise the axles 3” to help keep the rear end from draging whem backing up or going foward. The rear cargo drawer weight is a suspect. Airstream swears up and down that there is no weight restriction on them, but I don’t put anything heavy in mine. Lesson learned.
guskmg

[Alumaholic]

It captures the wisdom of the ages on the topic.
Nothing to add, but could not resist offering a loud cheer of agreement.
If you don't assess and deal with this obvious disruption of body and frame integrity, your Airstream will only be suited for what you have in mind as temporary, stationary lodging.
There is good news, however. Airstream motels are springing up all over the United States (and the rest of the world). Your Airstream is still a high value item even if it is never roadworthy again.
For example, Check out:
https://hotellunamystica.com/
Or this:
https://theshadydell.com/
I am not being dismissive or flippant about your situation. Only suggesting that you do not sell yourself short. Once you move into your new home, your Airstream can be repurposed.
Hope this helps!

[Swrider]

Hello everyone, its been a bit. So i continued with the planned gutting of the trailer, and surprisingly all i have found are signs of water leaks at different places, but so far i don't think i have any rot. More surprisingly, when i removed the bath the floor was there!!!
Didn't see any signs of rear end separation either.
All good things, in my opinion, but now im left wondering, how do i check the frame???
The initial plan was that i would need to replace the subfloor and therefore i would be able to see the frame. But having found that the subfloor is in really good shape i am hesitant to pull it.
So how do i check the frame, drop the belly pan and look from below?
I'll leave some pictures of how the floor looks; any comments and/or suggestions about its condition, or how i could better check the floor fpr rot are greatly appreciated.

[Alumaholic]

ACtually, your sub-floor looks pretty darn good.
As Belegedhel mentioned in his response to your first post, the easy check for frame separation is to stand on the rear bumper, first one end and then the other, and bounce gently up and down.
Frame separation is readily apparent if you see a gap between frame member and belly band open and close as you bounce. Nothing to it.

[Alumaholic]

Or better yet, have someone else do the gentle bouncing while you eyeball the frame member to body integrity.
Choose someone of average weight. These were never built to support much weight on the bumper.

[J. Morgan]

I wish mine had looked that good.

Build the trailer, chance are the fame condition is somewhere between "very good" to "good enough".