I recently took the shell off my 77 Sovereign
31. I have been asked a couple times to describe the process. I have a thread in the General Repair Forum if folks want to see the whole process of getting there so far. I do think it would be helpful to quickly go through what I did with some pictures and a video.
Note that the wood is attached to the shell using deck screws with a hole drilled out 1/8 inch in advance. The deck screws are generally used two at each connection to a rib.
The wood frame is pretty simple. I ran two segments of two 2 X 6 down the middle of the trailer and attached them to aluminum ribs which come down on each side of the big window fore and aft. I used carriage bolts to join them in the middle - two bolts at the front of the joint, back of the joint and middle. I used 16 ft lengths there - gives you about a 5 foot overlap. This is your main frame.
The first picture is the main 2 X 6 and where I attached them.
The second picture is of the middle where they overlap. Note bolts.
Then I put a 2 X 4 athwart ships 16 inches off the deck (to clear the wheel wells) on the two main ribs where the end caps meet the main section. There are about 5 or 6 ribs in the main section - spaced out evenly I put in three more sections giving 5 in total athwartships. These were attached to notched 2 X 4 cut to length to attach the main 2 X 6 to these 2 X 4 to mainly put the weight of the shell on the 2 X 6's. Then to alleviate any weight distribution issues we cut triangle sections at an angle and married them on the op of the 2 X 6 to each athwartship support.
The third picture is the front endcap and the fourth picture is the back endcap. The fifth picture is the notched 2 X 4 attachment to the main beams.
The last piece major work was to run 2 X 4 on top of the athwartship lengths along the length of the trailer to stop any twist. The ribs will hold the trailer up - they usually do every day. Some folks I have seen run supports up to the ceiling thinking they needed that support. In my opinion that was more support than was needed and made the whole thing heavier. We added one more athwartship beam and then (total 5) and then added the anti twist 2 X 4 on the top for the length of the trailer.
The sixth picture is of the anti twist boards.
The tricky part next is releasing the shell from the frame. The hardest part was the front (There were 3 - not one - riveted plates from the frame along the front shell - 2 of them are hidden behind ribs . . . so you have to take the rivets out from the outside up the rib aways - about 8 inches) and then decouple the adhesive - time consuming work.
The seventh picture is those front frame pieces.
There is a resting channel on the front endcap and rear endcap. Those bolts needed to be ground off. I am sure there are a thousand ways to do the bolt removal. The oscillating saw did not work for me nor did grinding from the bottom. It was less than 4 mins a bolt with the grinder. You will lose some aluminum but it was worth the time gained (my opinion).
The area between the front end cap and the door is wrapped different from the outside than the rest of the trailer. This means you have to drill out more rivets - and from the inside out as they are hiddne. The door screws go into the floor - they need to come out. For the remainder (easy part) I took out the rivets from the shell into the c channel. Then decouple the adhesive all along the channel. Do not forget to brace the door if you want to use it while the shell is off. Another alternative would be to take it off. I also added 2 X 4 across the bottom of the shell where it was detached - it was pretty floppy there and I wanted to maintain the integrity of the shell.
Picture eight is the door frame braced.
So when all the shell is clear of the frame you can jack it up enough to get the 4 X 4 under the main braces. Slow and sure and having someone with tools on the outside is essential. At this point it is time to make a decision about how you want to get the trailer out. I strongly recommend taking the wheel wells off - this means only about 4 inches of clearance is required. Also remember to support the middle of the main beams as you go up - each time you settle back down onto 2 X 4 blocks (you will need a $@#!load of them) try and balance the load on the main beams. Same principle applies when you get it onto the 4 X 4's.
Picture nine shows the whole frame piece off and ready to go.
I hummed and hawed at the Cinder Blocks -in the end they were by far the best thing to use. At $2.50 a block X 24 it was not a great expense. Note in the final picture ten the support in the middle off the beams underneath. We were worried. Also note the blocks on either side of the cinder block structure.
Pulling it off the two main issues were clearing the front 4 X 4 with the tires. What we learned was that off the frame the whole trailer rose about 3 inches or more - something I did not realize would be some much. I also forgot the back endcap frame attachment point was about 1.5 inches off the floor - I was trying to cheat by not having to raise the back as much as the front - mistake.
This is a video of getting the trailer out. We dug trenches instead of raising it more when we ran into an issue.