Bolt down system for truck canopy

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,849
Reaction score
1,116
Location
Campbell River, B.C.
It took a long time to find the exact canopy I wanted. Cab height, neutral white color, and aluminum base plate, instead of wood-core fiberglass. The roof is also cored with something that makes it stiff enough for me to walk on it. Not bad.

Unfortunately, that aluminum base plate proved flimsy and a few pot holes on the dirt roads quickly caused some damage to both the canopy, and my truck. Basically the bouncing and flexing caused the base plate to rip around the hold down clamps, allowing the front canopy corner to start bouncing.

I didn't want to add new holes in the truck so after a few months I had a brainwave. The rear tailgate latch uses two bolts on the bullnose era. Those bolts thread into a floating steel plate that's captured by some sheet metal tabs. This allows for easy adjustment and is very common on most vehicles. The door hinges of these trucks are adjustable in the same way. Anyway, the ends of these two bolts are long enough to just barely get a nut on them. You might be wondering how I intend to tighten a nut inside the rear corner stake pocket of the box. Well, you don't.

Instead, I needed a steel plate that was threaded to the right pitch and with two properly spaced holes. Since I'm a filthy pack rat, I still had the original box for my truck, What's left of it, anyway. And that meant I had two perfectly ready made plates.

I welded a threaded rod onto the plate, and bent it so that it came up roughly through the center of the stake pocket. This turned out pretty solid. Aside from being a much better hold down system, it also meant that the canopy can't slide around either.

It was easier to fab up something for the front pockets. I used some steel channel scrap to fabricate a long "L" bracket. This hasn't been road tested yet, but I'm sure it will hold up better than the usual canopy clamps I've been using up to now. Once finished, I panted it with zinc rich marine hull primer.

Building these components took a couple afternoons of work. Prepping the canopy and accurately drilling the holes took another whole day.
 

Attachments

  • IMG_1751.JPG
    IMG_1751.JPG
    437.6 KB · Views: 7
  • IMG_1752.JPG
    IMG_1752.JPG
    421 KB · Views: 7
  • IMG_1753.JPG
    IMG_1753.JPG
    322.6 KB · Views: 7
  • IMG_1756.JPG
    IMG_1756.JPG
    380 KB · Views: 7
  • IMG_1757.JPG
    IMG_1757.JPG
    280 KB · Views: 7

lotzagoodstuff

Supporting Member
Supporting Member
Joined
May 19, 2007
Posts
2,731
Reaction score
679
Location
Carmel, IN
Nice fabrication work ;Sweet Kudo's to you for being a packrat and saving the old bed off your truck. Nice write up/documentation too.

As an OBS with canopy owner, my view is pure jealousy.
 

Jesus Freak

Full Access Member
Joined
Apr 3, 2022
Posts
3,387
Reaction score
3,904
Location
Crestview, FL
Great job! I'm always looking for the right topper as well, but I want a janky aluminum one. If it's too pretty it'll mess up the look of my truck.
 

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
300
Reaction score
168
Location
Puget Sound
Looks super solid, nice. The bent threaded rods look like they're gonna start crawling away or something.
Slightly surprised the aluminum base was warping due to road conditions but always a good idea to beef things up. Better than c-clamps..
 

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,849
Reaction score
1,116
Location
Campbell River, B.C.
Leak tested it today. No water coming through at the bed rails but some of the windows will leak, if enough water overwhelms the tiny drain holes in the extruded window frames. I might be able to seal them up better but I'm pretty sure normal rain should be no problem as is. Rainy season is almost here so I'll find out soon enough.

The canopy door also comes down low enough to lock the tailgate at the same time. It won't keep a determined thief out, but better than nothing.

And lastly, I managed to salvage the aluminum tailgate cap from the old bed. It was badly mangled but after about 3 hours of straightening (yes, really) its good enough. If it wasn't for this, the new paint on the tailgate would quickly get worn off by the canopy door gasket gasket. Dust from the road is surprisingly abrasive so I was only using my spare "junk" tailgate up to now, and it wore through to bare metal in a few months.
 

Attachments

  • IMG_1087.jpg
    IMG_1087.jpg
    245.9 KB · Views: 7
  • IMG_1088.jpg
    IMG_1088.jpg
    225.4 KB · Views: 8
  • IMG_1089.jpg
    IMG_1089.jpg
    204.6 KB · Views: 9
  • IMG_1090.jpg
    IMG_1090.jpg
    450.7 KB · Views: 9
  • IMG_1091.jpg
    IMG_1091.jpg
    373.4 KB · Views: 9

gandalf

Senior Member
Joined
Jan 21, 2005
Posts
3,886
Reaction score
1,079
Location
CA &/or Maine
That's good work. It should serve you well.

However, I have a single reservation. Our truck beds flex quite a bit. Its the way our trucks are made. I've seen one rear corner of my truck rise and fall 7 inches while the other side was stable. The frames are that flexible. This is usually fine, until you put a shell/cap on the truck. When there is a shell/cap, you're asking the shell/cap to flex because it is attached so firmly to the bed rails. This can have bad results. This happens most in off-road rough terrain.

I've had 2 shells on 2 trucks. The first, bought second hand, had stress cracks at the rear upper corners. I pulled it off the truck when it arrived in Maine. My second shell, also second hand, at least, was given me by Calvin's daughter after he passed. This truck, pictured in my avatar, is 2 wheel drive and doesn't leave the pavement. The flex does not cause a problem.
 

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,849
Reaction score
1,116
Location
Campbell River, B.C.
Yup, flex is an issue. I'm hoping the fiberglass will be able to move with the bed. I did try flexing the truck once to test articulation, but never got to the point of actually lifting a wheel (there's a pretty big ravine on the other side of that rock!). Front and rear stabilizer bars are currently disconnected, to allow for more articulation, and less twist in the body. I'm still looking to try and stiffen the frame some day but can't settle on how to do this. Maybe some intermittent boxed portions? I'm not ashamed to admit losing sleep over that flex dilemma. But then I remember how long these frames last in their flexible form and start worrying about creating stress points that might crack.

I didn't quite catch the top of the box in these older photos, but if I had to guess, there is less than 7" total flex within the box itself.
 

Attachments

  • IMG_1189.jpg
    IMG_1189.jpg
    595.9 KB · Views: 6
  • IMG_1190.jpg
    IMG_1190.jpg
    770.8 KB · Views: 6
  • IMG_1191.jpg
    IMG_1191.jpg
    512.5 KB · Views: 6

DaveBen

Supporting Member
Supporting Member
Joined
Sep 29, 2010
Posts
1,949
Reaction score
663
Location
Ukiah, Ca
The pick-up bed is a box and it is unlikely to twist or bend which would damage your shell. I had one on two 4X4 trucks for years and never had a problem with the shell.
 
Top