Frame modification to remedy rear leaking

[dcole]

I've seen a lot of talk about different approaches to dealing with water entering the tail end of the trailer around where the bumper box attaches to the shell.

I'm considering notching my frame 1/2 to 3/4" deep at the rear edge of the shell and add some sheet metal to extend the shell down into the notch. Also, modifying the bumper box lid, probably just shorten it and leave a drainage gap so it doesn't touch the shell (adding a piece of angle to attach the bumper box lid to).

Has anyone else tried a similar approach?

[dcole]

Here are more images

[Belegedhel]

The approach that many of us (including myself) have taken is to leave the frame as it was designed, but then to insert an "L" shaped piece of aluminum along the back edge as sort of a flashing. The idea here is that water will run down the shell, and then instead of hitting the bumper trunk and being directed straight at the edge of the plywood, it will hit the horizonatl part of the "L" and get channeled away from the body of the trailer.

good luck!

[blickcd]

I'd like to see a photo of this fix and get a bit more detailed description. Not sure if the angle "flashing" is inside, outside, or between the two skins.

[Belegedhel]

The vertical part of the L shape goes up inside the outer skin.

[Greg1410]

dcole - I was thinking of doing the exact same thing. I am thinking that if one wanted to retain the same size bumper box, the frame would have to be extended slightly. Would love to keep updated on this - I many months away from this aspect.
Greg

[dcole]

I'll post photos when I finish my approach. I may not modify the frame rails. I'm most concerned with the flat plate that extends beyond the back of the shell. I plan to use angle iron to fabricate a frame cross support that follows the curve of the shell, and not extending beyond. Too bad I don't have access to a plasma cutter!

BTW, I'm not keeping the original black tank, so I don't have constraints that others may.

[sir_tob]

Originally Posted by Belegedhel

The idea here is that water will run down the shell, and then instead of hitting the bumper trunk and being directed straight at the edge of the plywood, it will hit the horizonatl part of the "L" and get channeled away from the body of the trailer

Just make sure to seal it correctly under the flashing to prevent 'wicking'. The flashing won't help that part... but it is a step in the right direction.

I do like the notch idea, if that is sealed correctly it could work.

[dcole]

Here are some follow up photos of what I did. I didn't end up notching the frame rails. I did replace my last cross member with one that is curved to match the rear of the shell. The original was pretty rough with rust and over zealous notching. I marked the shell curve on a piece of angle iron and cut it with an angle grinder with cutoff wheel. The first pic shows it tack welded in place and double checking position with the rear trunk cover.