Shell to Frame Alignment

[Dman]

Does anyone have a method of making sure that the shell, when set back down on the frame/floor, is set back on where it originally was before it was taken off, when doing a shell-off floor replacement?

[byamcaravanner]

Yes!

measure...measure....measure.

Take key measurements relative to benchmarks on the frame before you disassemble the trailer and create a drawing to use as a road map when reassembling.

[markdoane]

On some early models, there was a piece of angle iron in each corner that was drilled and bolted from the end of the outriggers and to the bottom edge of the end ribs. Measure from those holes both front and back, side to side, and diagonally and you will be sure it is put back in the original setup.

Not a guarantee that the factory had it square, but at least the skin won't be rippled.

[Petethefeet]

Ideally, from my experience, you would have measured and recorded as many relevant dimensions as you could think of, and taken loads of pics i.e. in between and overall , wall to wall both ways,where curves begin and end using a good point of reference as is already mentioned, I ended up running a centerline down the frame of the trailer and worked off that, eventually running profiles down each side with stringlines. As has also been mentioned, do not expect the original holes and/ or out riggers to be square or even line up necessarily, I found that it was easier to let the new plywood flooring be oversized slightly and trimmed it to suit. Also, the trailer I worked on had a steel plate that ran east/west on edge at the front of the cabin, that the front of the body slipped over and was fixed to. That pretty much located the front of the shell and I could work back from there. Good luck.

[byamcaravanner]

Originally Posted by Petethefeet

I found that it was easier to let the new plywood flooring be oversized slightly and trimmed it to suit.

Coincidentaly... we just took the factory tour and watched a new floor being assembled. That is exactly what was being done.

[FC7039]

Originally Posted by Petethefeet

....., I found that it was easier to let the new plywood flooring be oversized slightly and trimmed it to suit.....

I am at this exact stage in my rebuild. I have the shell off and the rough outline of the floor down. How do you dry fit the shell on the floor to get the final measurements?

I was able to jack the shell up onto blocks and pull the frame out from under it. I cannot see this in reverse as being very precise as to get good measurements.

I am considering building a frame to act as an overhead crane using a hoist. It would be one long beam that would span both the shell and frame. I would hoist the shell, slide it along the beam over the trailer frame. This way I could lower the shell and adjust it. The only issue is the cost of steel to make the frame and then what to do with the frame afterwards.

[urbanfood]

Originally Posted by byamcaravanner

Coincidentaly... we just took the factory tour and watched a new floor being assembled. That is exactly what was being done.

interesting, that is exactly what i was planning on doing.

dan & FC, the curved c channel at the base of the shell was in great shape so i'm going to be laying down the plywood a little big. then laying down all of the curved c channel at both ends which will fit exactly like old and then trim the plywood. then i will drop the shell down and fine tune the alignment. i also took a whole bunch of measurments.

one note, is my bellypan went on first and slides in between the shell and over the channel. i'm going to put the belly pan on after the shell and slide it up in between, haven't exactly figured this out but i'm sure i will once i get the shell in place.

[Petethefeet]

Originally Posted by FC7039

I am at this exact stage in my rebuild. I have the shell off and the rough outline of the floor down. How do you dry fit the shell on the floor to get the final measurements?

It feels like a long time ago now, but from memory, I re-used the old flooring at each end with the curves on, as templates. Using the original bolt holes as reference points. The flooring was not in great shape or whole, so I had to ease the curves to fill in the blanks . I compared the adjacent curves by mirroring them so to speak, and even they were not symetrical. That pretty much got me my end points and could work on from there straightening and even tensioning the shell slightly. The frame of the trailer was supported throughout the process ( and still is ).
.

I am considering building a frame to act as an overhead crane using a hoist. It would be one long beam that would span both the shell and frame. I would hoist the shell, slide it along the beam over the trailer frame. This way I could lower the shell and adjust it. The only issue is the cost of steel to make the frame and then what to do with the frame afterwards.

For me, I was reluctant to put anything overhead above the trailer for fear of accidental damage. As long as you can get the frame under the shell again, I would think it possible to reassemble reasonably straight forwardly. The shells are not that heavy when stripped out, and have a bit of flex, I ended up putting the sovereign shell back on by myself in fact. It was a bit of fluffing around, but not impossible ( pics shown pre new floor ). As the trailer frame was supported, I jacked the shell down, slowly, off the floor ( doubled up the area where the jack was with offcut flooring), the shell was held from sliding laterally with tie-downs, anchored at one end, and slid the temporary bracing/ timber out. I'm sure there are threads here demonstrating ways to do what you want to do, in much more clarity than I can explain, and my way was just the best way I could think of under the conditions, there could be easier ways. But essentially, I think it is all pretty methodical.

[Petethefeet]

Just realised part of my reply is hooked up in the quote, second paragraph is part of my reply. Dope!

[vhord]

Originally Posted by Dman

Does anyone have a method of making sure that the shell, when set back down on the frame/floor, is set back on where it originally was before it was taken off, when doing a shell-off floor replacement?

I am replacing my subfloor with the shell on but I had the same question. Then in the middle of the night I had a realization that the bolt holes at the end of the outriggers have to match up with the holes in the c-channel where it was originally bolted down. From underneath I drilled through the hole in the outriggers, through the subfloor, then stopped. From inside I then lined up the hole in the channel with the hole in the subfloor, dropped a bolt through and tightened them up. One place I had to use a ratchet strap to help pull the wall back in and hold it until I could bolt it.

[Wabbiteer]

To get final alignment once the back sheet replacement plywood was in and binding any movement I stood on a 2"x8" board length and tapped the end gently with a sledge hammer, the opposite board end pushing the C-Channel to where needed and my weight on the board keeping it from rebounding until I anchored the 2"x8" in place with wood screws and my cordless drill. Amazingly it worked very well being able to tension one side up and then work on the other, lock it down, release the first side and repeat...

[monocoque]

Originally Posted by Dman

Does anyone have a method of making sure that the shell, when set back down on the frame/floor, is set back on where it originally was before it was taken off, when doing a shell-off floor replacement?

What model of trailer do you have?

Sounds like a good technique Vernon.

On my '75 Ambassador there are four bolts with nuts and washers anchoring the shell to the frame. Two in the front and two in the back. I'm not talking about elevator bolts through the outriggers. These bolts are through the frame itself. Each bolt has a large square steel "washer," locking round washers, and a nut. See http://www.airforums.com/forums/f36/...rot-39673.html post number 198 for photos of these bolts. If your trailer is similiar it seems to me you should be able to square the shell using these four cardinal points.