Chevy & GMC Vans

Hey all, got a weird question for you: Has anyone drilled into the area where the top of the body-side meets the roof? (Specifically, the area above the rear-most quarter window.)

I know there's a folded box-section up there above the window, where the roof and side panels were joined, but I'm not sure what might be "inside" that box. This area here:



I'm in the midst of a project to create a side-mount rack for my rear-quarter window. I'm emulating the functionality of a similar thing from CampervanCulture for vanagons. That one clamps onto their drip-rail, which of course, we don't have.

You can see that I've been working up some brackets that attach via some existing holes in the roof (made for my pop-top conversion, these thread into a 3/16" backing plate that runs under the hinge.) The idea was to mount some L-track to these brackets, spaced out from the window by an inch or so. I've got L-track fastened directly to the body on the bottom under the window (blind-fastened into RivNuts inside a similar boxed section of bodywork, since I couldn't put backing plates inside the box). Now that I've got the brackets basically done, I took a step back and was wondering if I wouldn't just be better off doing the same thing on the top-side and fastening the track directly to the bodywork there. The problem, as stated above, is that while I know there's a boxed section of sheet metal, I'm not as sure about how it's formed, and I'm worried about drilling in to try to put RivNuts in and finding out that there's an extra fold or something inside that creates a problem and now I've got (more) un-used penetrations.

Anyone know for sure what's up there? Or just I just stick with Plan 'A' and hang the brackets off the roof. On the plus side, I've got a solid backing system there. On the negative, there's a bit of a lever-arm since the brackets have to come out under the pop top and space out from the glass without touching the side.

Thanks!

I can't help but interesting topic as I have my headliner out and looking at reinforcing the roof for a roof top tent and probably a custom rack.
timely topic!

Hi,
If possible go to Pic your Part and find an Astro cargo van. Photograph the inside sheet metal.

Good luck.

I use Riv Nuts also with plier like setting tool which goes to 3/8" aluminum.

There are also heavy duty Riv nut setting tool from McMaster Carr and Grainger, that use wrench to set Riv nut,

Perhaps you could install a square U bolt from inside the roof to create attachment points outside with stronger spread over more sheet metal?

AP

Astrophysics wrote:Hi,
If possible go to Pic your Part and find an Astro cargo van. Photograph the inside sheet metal.

Good luck.

I use Riv Nuts also with plier like setting tool which goes to 3/8" aluminum.

There are also heavy duty Riv nut setting tool from McMaster Carr and Grainger, that use wrench to set Riv nut,

Perhaps you could install a square U bolt from inside the roof to create attachment points outside with stronger spread over more sheet metal?

AP

I've had the headliner down, so the inside sheet metal isn't the problem. The issue is that right at the top there is where the side and top panels were bent to interlock with each other. It creates (at least) a blind channel (there's basically a sheet-metal tube running front-to-back right at the top corner). My concern is that the channel might not be hollow, but rather like a U with an extra "middle" fold, because I have no visibility into how they bent those panels prior to attaching them together. If that's the case, then when I go to drill, I might find the bit walks right into the end of a one of the folds.

The scrap-yard is a good idea, though, since I could probably drill the body of a clapper van without anybody caring (or knowing...)

Hi Again,

Yes, you can bring cordless drill and do a test hole or two.
Be carefull not to get your wrist injured if the drill bit binds when it jams on the second edge of sheet metal it could torque back hard!

Someone told me to home the drill with your left hand with light grip so if the drill bucks you are less likely to sprain your wrist.

I do this method when using 3" hole saws in plywood since I have had it buck .

AP

Just a long overdue follow-up to this question, in case anyone else is seeking similar answers.

I took a cordless drill to my local pick-n-pull today while grabbing a couple of other parts. I drilled a series of test holes into the area of the van side-wall, just above the rearmost quarter window. I am really glad I trusted my instinct and rigged up another way to suspend stuff (from the roof area, using the same bolts that fasten my pop-top hinges), since I'm fairly certain someone would have a lot of trouble trying to put riv-nuts or other blind fastener into this area.

There is the outer sheet metal, then there is some sort of secondary bit of metal, probably about 1/4" or so behind this. (As above, I assume this is some piece of the roof material that has some interlocking origami when they're joined together). Looking at my collection of steel rivnuts, the "clamping range" on all of them is such that I don't think you'd get a good compression of the nut and good mate to the material here. The gap between the two pieces is definitely too shallow to insert a rivnut and have it grab only the outer skin.

Now we know!

Hi,

Good work on that investigation. Self taping #12 0r #10 screws could hold some bracket. And also put JB Weld epoxy on the bracket to add additional strength.
At least the sheet metal gauge is pretty thick on our Astros. Wow, the new Ford Transit vans have very thin sheet metal.

AP

You may have found similar situation to the top ribs, where the top panel is supported above the rib with some sort of semi-rigid foam like adhesive material.
Whatever that material is, it looks like it was extruded as a bead, and then the top section installed, so the entire top panel is sort of glued to the interior ribs.