I had to build a dirbike rack for the box of my new Toyota toy hauler. Been thinking about this version for a couple of years and finally built one last weekend. The bonus is that it is completely adjustable and easy to bolt additional brackets to (you can see two that I added). I also wanted to reinforce the box so that cinching the tiedowns doesn't bend the box front (as it did in my last Chevy). In past trucks I used a notched 6" steel channel but I wanted to make something adjustable that is easy to add to. I had planned on installing 2 rails, but I ended up using the top OEM toyota rail and just added the 2nd rail. Rail material is called "unistrut". Unistrut is a preformed channel that is made for constructing industrial brackets and supports and has a bazillion attachments available - kind of like an industrial mechano set. It is available at any industrial electrical wholesaler. A 10' galvanized length with 6 springnuts (the threaded attachments that fit inside) cost me $12.00. I had originally planned to use 2ea 5' lengths but the toyota rail matched up great. I made inserts for the toyota rail from 1" steel flatbar with a 3/8" threaded hole. The new rail is through bolted at each end (1/4") and then rivetted (x4) to the box in the spots where you can't reach (or see) the back. Seems to be strong enough but time will tell.
Parts list:
10' 7/8 x 1-5/8" unistrut P3300
6 spring nuts
3 3" lengths of 1x1/4 flatbar (with a centered 3/8" threaded hole)
3 14" lengths 4" steel channel.
9 3/8" bolts
some 3/16" x 1 rivets
Hope this helps someone, or at least gives them some ideas. Cam.
pic1: side view of the rail with a springnut
pic2: insert for the Toyota rail
Pic3&4: Installed.
