Just put my Bakflip F1 and BakBox on yesterday and I thought I would share something that definitely seems to have helped "firm up" the box.

I don't do construction for a living so I went with the BakBox just to have a dry and secure place to store tools, trailer and towing equipment, and so on for infrequent use. I know it's not as easy to get into as a regular toolbox, but I also didn't want the hassle of a large toolbox obstructing vision (and then the inability to use a tonneau).

When I installed the box, I have to say it feels grossly overpriced for what it is. I guess there is a very small market for under-tonneau toolboxes (that aren't just regular toolboxes sitting in the bed bungeed to a hook) so I understand they can charge what they do. I was able to sit on it so it does support 200#, at least, in addition to whatever is in the box. In any case, the box itself is short by about an inch in my '12 FX4. This is fine given the ability to "expand" the box, but it just seemed loose. This left me with a 1/2" gap on each side where the exposed ends of the fiberglass and foam and the aluminum side bracket.

What I did was cut some 1/2" plywood to 10 3/8" x 11 1/8" and simply drop it in between the fiberglass panels and the side bracket. This helps provide some friction-based security by preventing any possible side-to-side movement of the fiberglass panels. I think tonight I will cut some more plywood to fit inside the box, thus providing some further stability. I guess you could also use 3/4" plywood or 4/4 lumber and route a channel out. If you didn't care about the ability to fold out of the way, you could also screw the wood in from the outside of the bracket.

It's not necessary and you shouldn't have to do this after spending $200+ on a small and overpriced box, but it does seem to help a lot with the "firmness" of the box.

 

Pictures of said box?

 

I had the same gap when I first put mine together but I just took it back apart and re-drilled the holes after measuring carefully and when I put it back in it fit like a glove.

 

I'm not sure what you mean. Juts going from memory here, the distance between the rails is about 59 1/4", give or take. The panels themselves that make up the box are about 58" exactly, and the aluminum brackets are about 1/16". If you have the brackets pushing against the rails, then you have no choice but to have about a 1 1/8" gap (9/16" each side) between the panels and the bracket. If you tighten it up, then the box itself can slide side-to-side by 1 1/8".

I will post pictures once I add more wood and paint it black. As a test I used some stained panels I had around the shop, so it's not exactly "appearance grade" at this point.

 

Oh. I get it now. Yes I do have a gap between the panel and the bracket. When I first put it together I put the panel flush to the bracket and it (the bak box) was almost to short to sit between the sides of the bed. So I guess I misunderstood what I read. Sorry bout that.

 

Mine seemed to spill open at the time and I wasn't happy until I got some more velcro and redid the sides. It would keep dropping the high lift jack I keep back there. Now the jack, three way hitch, and a couple of warning signs stay there out of the way. Cost less than 6-7 dollars for the velcro.

 

I had to add more Velcro as well... 1st time I tried too collapse the box all the velcro peeled (sticky side) off the box.

That's been the only issue I've had though.