Hidden Front Seat belt upper mounts

Includes seating, upholstery, door trims, dashboard and heater.

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138
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Hidden Front Seat belt upper mounts

Post by 138 »

I would like to fit lap/sash seat belts to my FB, and have seen "hidden" types (where the big ugly bolt head is not visible from the outside). I have tried finding pictures on this site, but it comes back with "404 error- something about being moved". Anyone have a photo of their "hidden' mount, or let us in on the secret? It looks like a tapped captive plate may work, but I haven't started taking the trim off around there to see if it will.
EK283
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Re: Hidden Front Seat belt upper mounts

Post by EK283 »

Check this out, thats what I did.

http://www.fbekholden.com/forum/viewtop ... &start=255

Click on the photos and open them in another window and they will be clear of the photobucket logo.

Greg
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ardiesse
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Re: Hidden Front Seat belt upper mounts

Post by ardiesse »

This is a job best done with the interior stripped out of the car. I cut through the weld joining the inside top of the B-pillar to the roof rail (FC, but I think FB should be the same), then drilled out about a foot of spot-welds where the inner door rubbers go. I welded a wheel nut to a piece of 3 mm sheet, and contoured the sheet to sit snugly against the inside of the B-pillar. Sitting inside the car, I decided on a good height for the top seat belt bolt, marked up the pillar for the seat belt bolt hole and four plug welds. I drilled the holes, bent the inside of the B-pillar inwards enough to admit the anchor plate, and lowered the anchor plate inside the pillar, hanging off some bent wire. When the seat belt bolt hole was aligned, I screwed a 7/16 UNF bolt into the anchor plate and tightened it up against the B-pillar. Then I plug-welded the anchor plate to the pillar, plug-welded the two halves of the B-pillar back together, seam-welded the cut at the roof rail, and dressed the welds down.

If you're not doing the seat belt installation as part of a restoration, I'd think twice. The B-pillar door seals, fixed glass, headlining and seats will have to come out. Plus you'll have to protect the door glass, dash and interior paint from angle grinder sparks.

Rob
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Harv
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Re: Hidden Front Seat belt upper mounts

Post by Harv »

Step 1 is to identify who has to certify your seatbelts, if anyone. As an example, in NSW you can have either an engineer write a certificate, or an Authorised Restraint Fitting Station. Some people choose not to certify at all. If you do need to certify, find out what the certifier will accept. As an example, the option I will give below was accepted by an Authorised Restraint Fitting Station, but my engineer would not do so.

If you have a utility, you do not need to strip all the headliner or cut/weld. Strip back the B-pillar trim, simple drill, and install captive plate with pop-rivets.

If you have a sedan/wagon, you may need to do the cut/weld trick. Another option is to drill a hole in the B-pillar a little bigger than 1" diameter. Make a captive plate that is 1" wide and 6" long. Slip it into the B-pillar on fishing line, pull it up into place, and pop-rivet. The seatbelt sash guide then covers the 1" hole. This works if your certifier is following NCOP, which specifies and area, but not the size of the plate. If your certifier is fussy and wants you to meet the VS5B ADR, then it won't work (as VS5B specifies a 75mmx50mm plate). Some people baulk at the 1" plate width, thinking it will pull out of the pillar. Think about the "Frankenstein" bolts in many old B-pillars... that 1" plate has a lot more surface area than the area under the head of a 7/16-UNF bolt. It will take sixteen times more load before it pulls out.

Your certifier may also get fussy on bolt separation on the floorpan (it took a full days work to demonstrate my wagon was compliant... lots of maths), plate thickness (3-4.5mm in NCOP, 3-4mm in VS5B), nut type (I used an 8mm tapped plate in my wagon... and had to re-do it as the engineer was not happy that an 8mm plate has less thread engagement than a 7/16-UNF bolt), nut type (NCOP specifies Grade 8 fasteners, so an unmarked wheel nut may not be acceptable) etc.

I've got a good write-up that describes how to comply with NCOP, with pictures and calculations from my wagon. It still needs a tidy-up before posting it here, but if you want a copy of the draft flick me an email address and I'll send it to you.

Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
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Re: Hidden Front Seat belt upper mounts

Post by EK283 »

Yeah,

Funny that Harv, I have read until my head hurts and can't find anything in relation to the nuts themselves.

There is lots of reference to the bolts being high tensile, mounting positions etc but no specific reference to the nut part (unless I'm missing it).

Greg
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FJWALLY
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Re: Hidden Front Seat belt upper mounts

Post by FJWALLY »

EK283 wrote:Yeah,

Funny that Harv, I have read until my head hurts and can't find anything in relation to the nuts themselves.

There is lots of reference to the bolts being high tensile, mounting positions etc but no specific reference to the nut part (unless I'm missing it).

Greg
I used the approved bolts and nuts and plates that were supplied and had them welded in - will troll through the build photos and see if I can find some good ones


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138
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Re: Hidden Front Seat belt upper mounts

Post by 138 »

Thanks for all the replies. I've installed many rears in early Chev's , Pontiacs, etc, just so I could strap the baby seats in, but never bothered with fronts as they are not required here (S.A.) if never originally fitted.(before '66).
Thats a very neat installation EK283, and thanks for the Photobucket tip. Back to the shed for more thinking along the lines of modern cars with integral seat /seat belt mounts where the seat mounting also secures the seat belt. That may work for just lap belts.
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FJWALLY
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Re: Hidden Front Seat belt upper mounts

Post by FJWALLY »

All I could find - must be more somewhere ImageImageImageImageImage


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Harv
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Re: Hidden Front Seat belt upper mounts

Post by Harv »

EK283 wrote: Sun Apr 26, 2020 8:23 am Yeah,

Funny that Harv, I have read until my head hurts and can't find anything in relation to the nuts themselves.

There is lots of reference to the bolts being high tensile, mounting positions etc but no specific reference to the nut part (unless I'm missing it).

Greg
You're right. The LK2 checklist asks "Are all anchorage bolts specified as 7/16 inch UNF SAE Grade 8?". My engineer interpreted that as the nuts also having to be Grade 8. Had to make a trip to Lee Brothers to find some :(.

Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
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Errol62
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Re: Hidden Front Seat belt upper mounts

Post by Errol62 »

Sorry to digress on your thread 138, on the commercial ute van fitment. Looking at FJ Wallys last photo has me wondering about alternatively mounting the inertia reel on the cabin wall rather than using the L brackets and mounting to floor. With the six seaters I think the bracket a good way to go if you don’t want to perform surgery on the lower b pillar. Harv has done both types of install. I think you used the brackets in Grace’s ute Harv.


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Harv
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Re: Hidden Front Seat belt upper mounts

Post by Harv »

I used the brackets in Graces ute, mounting to the floor pan.

If I was working on a painted car, I'd use that method. If the car was in bare metal/primer, I'd use the B-pillar for the lower mount. The L brackets sit directly on the floor. The floor pan is far from flat, which can tilt the reel. The little inertia unit then tends to lock up unexpectedly (can't put the belt on, move the car a bit and the unit unlocks and you can). I had mounted Grace's reels as close to the B-pillar as I could. After driving for a while, it was crapping me when the belts would lock. No room to shim the reels back to square, so gave the B-pillar a tune-up with a BFH (I think the official description is "recessed") by 2-3mm to let them sit square.

Cheers,
Harv
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Errol62
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Re: Hidden Front Seat belt upper mounts

Post by Errol62 »

Thanks Harv. Your take on using the rear cabin wall?


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FJWALLY
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Re: Hidden Front Seat belt upper mounts

Post by FJWALLY »

we welded a much larger plate in behind the real - think it was around 120mm x 120mm and did multiple spot welds as well as the proper welds around edges - it would have to rip the whole rear panel off.
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Re: Hidden Front Seat belt upper mounts

Post by 62ekute »

Harv wrote: Sun Apr 26, 2020 7:11 am
If you have a utility, you do not need to strip all the headliner or cut/weld. Strip back the B-pillar trim, simple drill, and install captive plate with pop-rivets.
that's my plan, after seeing FJWally's pics


for info only - here's the top mounts I pulled out of mine

top.jpg
top.jpg (41.72 KiB) Viewed 792 times
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Errol62
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Re: Hidden Front Seat belt upper mounts

Post by Errol62 »

Oh ha ha ha ha.... what were they thinking.

May well go this way Rob but I would possibly sandwich some 18# sheet folded to run aft and stitch to floor. That panel is spot welded 20# and could possibly be ripped out along the bottom in extreme circumstances, in which case we would probably be toast anyway.


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