Mounting solar panels using factory roof holes

Wildspirit · 2025-10-04T14:14:39-0400

I want to add more solar to my roof, but the cieling is already paneled and I don't want to dissasemble it so I can through bollt the mounting brackets like I did with the original panels. I am looking at the facory mounting holes that have rubber inserts in them and wonder how they can be used. Does anyone know about those?

PS, I wont use VLB tape to mount solar panels.

Thanks for your input and suggestions!!!

gregoryx · 2025-10-04T15:46:40-0400

Wildspirit said:
I want to add more solar to my roof, but the cieling is already paneled and I don't want to dissasemble it so I can through bollt the mounting brackets like I did with the original panels. I am looking at the facory mounting holes that have rubber inserts in them and wonder how they can be used. Does anyone know about those?
...

They are already threaded - M8, IIRC? Documented here many times. Bad news is they don't always line up exactly and you may need to trim the steel.

Be sure to seal them up real well after. They're prone to leaking.

barrycburton · 2025-10-04T20:23:48-0400

The Far Out Ride post was the best overview I found- Ford Transit Roof Rack: Best Option & How To Install - FarOutRide

I spent a bunch of time trying to figure out how to use them to mount solar panels without using a rack but they aren't located in a great spot for that. On a Sprinter they are located in the gutter / channel near the outside of the roof but on the Transit they are located a couple inches inboard so underneath where my solar panels are going.

Weather Guard makes a low profile channel kit that mounts to them that looks like it would work well if my solar panels could go a couple inches inboard- Van Accessories

I was thinking it wouldn't be too hard to make my own version of that out of aluminum flat bar and t-track. But ultimately I realized I was creating this complex armature to adapt the factory mount points to where my solar panels need to go just that I could avoid creating new holes for through bolting, but the factory mount points are also holes that I would be opening and needing to seal in the same way so why not just put the holes in the right place and skip the convoluted mess. 😂

gmoneda · 2025-10-04T21:52:58-0400

I used the factory rack holes, crossbar, for rack and panels. Not as nice as may of the racks seen here, but solid. As noted above, I had a little mod needed and careful but copious gutter sealant. You can do it

Wildspirit · 2025-10-04T23:22:58-0400

I just finished looking at my roof and now that i know there are threaded holes under those seals, I think i am going to get 2 pieces of 4" x6' aluminum flatbar and bolt it athwartships across the van. Then bolt aluminum L (angle)n iron to the flat bar and brackets to the angle iron. The panel will attach to the brackets on the iinside and outside of the solar panels. They are 20x45" and will fit on either side of my MaxAir fan and but up agains the 2, 220W panels I already have. I wont have to take my cieling apart to mount them.

Has anyone done that or have any comments? I looked at Orton's roof and he mounted his panels by through bolting angle iron to tne roof and attaching brackets to correct the angle of the roof.

papab · 2025-10-05T20:37:48-0400

Wildspirit said:
I just finished looking at my roof and now that i know there are threaded holes under those seals, I think i am going to get 2 pieces of 4" x6' aluminum flatbar and bolt it athwartships across the van. Then bolt aluminum L (angle)n iron to the flat bar and brackets to the angle iron. The panel will attach to the brackets on the iinside and outside of the solar panels. They are 20x45" and will fit on either side of my MaxAir fan and but up agains the 2, 220W panels I already have. I wont have to take my cieling apart to mount them.

Has anyone done that or have any comments? I looked at Orton's roof and he mounted his panels by through bolting angle iron to tne roof and attaching brackets to correct the angle of the roof.

I used 3x1 (? I'd have to double check that) AL angle. One side was bolted to the OEM nuts, the other to the panel. Pics here:

https://www.fordtransitusaforum.com/posts/1349568/

I used some brackets and VHB in the center

chicagoandy · 2025-10-05T07:37:48-0400

Check out diyvan.com

They sell a lot of components that make building your own rack easier, including how best to use those threaded holes.
He's also got some decent YouTubes. @Hein

Bargeman · 2025-10-06T14:00:07-0400

chicagoandy said:
Check out diyvan.com

They sell a lot of components that make building your own rack easier, including how best to use those threaded holes.
He's also got some decent YouTubes. @Hein

I used Hein's components for a roof rack to mount my panels and used the existing holes for the rack. Works a treat.

gregoryx · 2025-10-05T13:39:09-0400

I haven't mounted them yet... but I have these in the box. Best price I've seen by more than 2X. Then put on any rails you like. I'll be mounting rails front-to-rear again, then cross-members for the panels. Undecided how much of it will be 8020 again vs angle-L; either way, pretty simple. And affordable.

Wildspirit · 2025-10-05T14:09:31-0400

Thanks for the referral. Unfortunately on back order. But I would get them if available now. I realized that I would need fairing, which really complicates the build. I have to build an elevated rack to mount the fairing to. Now I am thinking 80/20 instead of simple flatbar. Some people say their fairing makes more noise and decreassed mileage. Sounds like a new can of worms.
BUT..... I just discovered this kit. Its only 192.00 and could solve the rack issue.. Has anyone tried it?

Weather Guard Van Equipment Mounting Channel Kit for Ford Transit | U.S. Upfitters

Weather Guard Van Equipment Mounting Channel Kit for Ford Transit

www.usupfitters.com

gregoryx · 2025-10-05T18:33:13-0400

why do you think you need a faring? Just put the panels on. As low to the roof as possible without touching.

Wildspirit · 2025-10-05T20:08:02-0400

am glad you asked that. When I put the panels on the roof as a mock upthey do not extend forward of the flat part of the roof. I was thinkiing they would be over the curved part and a lot of upward rushing air hitting the panels woule make a lot of noise, and cost me gas mileage. If I can mount 2, 72"x4" pieces of flatbar across the van and secure them to the factory mounts with a single 8mm bolt, then I can install Z mounts on the outboard end of the flatbar and along the centerline of the flabar to attach the solar panels. That would be the lowest profile mount possible. It would be simple and cheap to do. Does anyone think thats not a good idea?

gregoryx · 2025-10-05T20:48:53-0400

Wildspirit said:
...
am glad you asked that. When I put the panels on the roof as a mock upthey do not extend forward of the flat part of the roof. I was thinkiing they would be over the curved part and a lot of upward rushing air hitting the panels woule make a lot of noise, and cost me gas mileage. If I can mount 2, 72"x4" pieces of flatbar across the van and secure them to the factory mounts with a single 8mm bolt, then I can install Z mounts on the outboard end of the flatbar and along the centerline of the flabar to attach the solar panels. That would be the lowest profile mount possible. It would be simple and cheap to do. Does anyone think thats not a good idea?
...

Personally not a fan of hanging over the sides... but in the front, it's really not a big deal.

These don't make noise. And we still get as much as ~15mpg if we drive slower - ~11-12mpg if I'm driving 80+ mph.

These are mounted on top of 30mm cross-bars because I built it to tilt up - which I later abandoned and have never bothered to disassemble and rebuild the top. This setup is using DIY roof-mount brackets to 30mm 8020 rails. I certainly won't be going to this level of hassle and effort again; but it confirms that NOT having a faring doesn't necessarily create noise or have a super-negative affect on mpg.

Wildspirit · 2025-10-05T23:17:59-0400

Thanks. what brand of VLB tape have you used? I have tried it on small exterior items and it hasn'
t worked very well.

Wildspirit · 2025-10-06T14:33:14-0400

Yes thank you. I would buy those if I was making a raised rack to accomodate fairing. I am going with flatbar for low profile and see how that works for noise and gas mileage.
Thank you everyone, I will report back.

gregoryx · 2025-10-06T16:45:27-0400

Wildspirit said:
Thanks. what brand of VLB tape have you used? I have tried it on small exterior items and it hasn'
t worked very well.

Only 3M VHB. Which covers a LOT of variations.

Wildspirit said:
Yes thank you. I would buy those if I was making a raised rack to accomodate fairing. I am going with flatbar for low profile and see how that works for noise and gas mileage.
Thank you everyone, I will report back.

Ideally, you still want mounts because of the angle - assuming you're mounting panels that cross the roof. If you're mounting at the angle of the factory mount points, they'll need to be angled UP toward the center of the roof. If you're running ACROSS the roof, then the mounts just need to be tall enough for a cross-bar (or the raw panel).

Easiest approach is to get (or make) mounts, then run aluminum angle-L and seat the panels into the L on either side - assuming the panel is the perfect width.

If the panels are to be mounted front-to-back then the easiest / most-secure is to include angle-L that crosses the roof and drop the panels onto it.

Sams stock van · 2025-10-06T16:56:31-0400

Here's a couple of pics with mounts from DIYvan and aluminum angle. I have less than a half inch clearance at the roof crown. I wouldn't go lower.

Why flat stock to span side to side? Seems like it would flex too much unless it was thick. Aluminum angle raised my panel 1/8" and resists flex much better.

Mounting solar panels using factory roof holes

Weather Guard Van Equipment Mounting Channel Kit for Ford Transit | U.S. Upfitters

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