I've been meaning to do this for awhile. Since next year I'm hoping for more camping/relaxing/exploring than I've seen in the last 4 years, it was about time.
I started by measuring some of my camping gear. This gave me a base line for height and length that I might need - a few items won't fit, but they can be strapped down on top of the platform (like the cooler). You can see that alot of items measure close to 10 inches or half of that (stackable)
Here are the plans I'm working from (no fancy Sketch Up for me, this is on the back of an envelope). I'm not planning on drawers, but I can always add them, and if I do they will extend 1" past the tailgate (no need for overly beefy slides). I have ~26" of reach with one arm, so I can easily get to anything at the back. The front compartment is going to have a cut out lid for the less frequently used items (dashed line). I plan on using piano hinges for the sleeping leaves (seats down) and probably solid wood instead of plywood - I'm thinking of short hinged legs extending to the seat back to support the weight along its length, but I may have to go with legs to the floor if that doesn't work.
I used 1"x10" (5 - 4' lengths)for the uprights and a single 4x8 sheet of 1/2" "project" plywood for the top and bottom (ignore the cubby divider, I didn't notice it was warped when I bought it - need to get a new one). Originally I was only gonna use the plywood for the top, so it would have only taken 1 sheet for the gear box and fold over sleeping leaves, but I decided to use plywood on the bottom to reinforce the uprights, keep them verticle and make sliding it in/out easier. The front bulkhead is angled to follow the seatbacks and will provide a lip for the sleeping leaves to rest on. The fold over leaves are split so I can still have one passenger in back if I want. I would have removed the rear seat behind the driver completely, except that we'll need the full length rear seat when we get another dog. All of the uprights are glued and screwed. The top will also be glued/screwed to the uprights, but the bottom will only be screwed. I This is where I'm at currently:
with the top on (I had to flip the Hi-Lift so the pins are facing left to fit the box in)
Jerry can fits perfectly here. I'm going to make a 3 legged strap specifically for the jerry can to hold it in place (both sides and one over the top).
Here's my clearance on the top with the tailgate closed. If someone breaks the rear window they still won't be able to unlock the tailgate to get to anything in the cubbies.
The next step is to weld 4 nuts onto the roll bar so I can install screw eyes and turn buckles to hold this down and keep it from moving (think sudden stops). I was thinking of using the factory forward tie downs, but this barely fits between the wheel wells, so there's not enough space to use them. I also need to borrow a 3/4" dado blade and make the uprights into 1/2 engineered I-Beams so I can raise the top 3/4" (or just sandwich 3/4" thick furring strips between the top and uprights) - I forgot that marked wood size is never actual size, so my 1"x10" uprights are actually 3/4"x9 1/4" which would make the sleeping leaves angle up towards the front in order to clear the top of the seat bottom. Final step will be a healthy coat of white oil based latex on the inside and some low pyle dark grey carpet to wrap it in.
So what does everyone think - am I off to a good start or missing something that can still be worked into the plans at this stage?