Seat belt mounting holes

[steven]

I need to add seatbelts to my '65 cab that didnt have them. How do you guys suggest I do it correctly? I want to put my 2 points in from my '67 in first, and when I have more time and $$ I'll put some better 3 points in. I was thinking of welding a decent sized plate with the fine thread nut for the seatbelt bolt welded onto it, then welded to the same panel where the seat bracket is welded to.

If someone would measure where the (four, I think?) seatbelt bolt holes where the bolts go, I would really appreciate it.

[nfury8]

The stock mounts are prevailing torque nuts - Tapered all metal lock nuts.
This provides extra safety by keeping the bolts from loosening.
Does your truck have a shelf for the gas tank? I didn't think the earlier ones did,
but don't know when this changed. The later trucks have the mounts in the vertical
face of the shelf. The boxed shape of the shelf provides extra strength. If you have
a shelf, consider mounting to it. If not, the front seat mounts for a crew cab would
be a good model. The crew cabs have the center seat belt mounts on the floor, surrounded
by a 3"-4" wide and ~3/16" thick washer, with a curved lip for added strength. The outer
mounts are right next to the B pillar, in the floor, and top of the rocker area. The rocker
adds extra support in this case.

Not sure on the third point. Does your 67 have the third point in the back pillar?

[steven]

Thanks, guess I should have clarified a little more.

My '67 cab was junk, so I tossed it. It had seatbelts. The '65 parts truck I used had an ok cab that I fixed, and put on my '67 frame. So now I dont have belts...

Yep, there is a shelf back there. Pretty sure every cab has it. I would just weld a nut flush with the outside of the vertical part of the shelf, but I dont know if thats strong enough. Thats why I was thinking more of like a plate. Were the factory nuts just welded to sheetmetal, or was there a plate back there too? I should have looked closer when before I tossed my cab...

[mightydodge]

I had a similar situation with my 1968 D-100. The cab was trashed and I had to replace with a 1965. I called up one of the seatbelt manufacturers and got a hold of four backing washers. The nice big, thick ones for providing reinforcement. Then I welded a nut to each of the washers. Then I grinded one side of each of the washers flat. I slid the washer-nut combo inside the box below the gas tank until it lined up with the seatbelt mounting hole. Then I ran the bolt in.

The reason I grinded off part of the side of the washer was so it would be flat against the floor boards. That way, when I ran in the bolt, the nut and washer couldn’t turn; the nut-washer could only be flush against the seatbelt mounting hole with flat side of the washer pointed at the floorboard.

[Hobcobble]

My '65 D100 was already retrofitted with belts. The previous owner popped
4 holes in the floor near the gas tank shelf and used standard 1/2" bolts
and 3/16" backing plates under the cab.... yes.... a "barn job"... but it
works.
John

[nfury8]

I am sure there is a plate inside the shelf, the sheet metal is the same thickness as the floor and the floor has reinforcements. Although I haven't checked.

I like MightyDodge's approach. It would probably be best if it was welded, but the surface area is more important. However, how did you handle the middle points?

[Cageman]

What I would do is cut a piece of 2 by 3 by 1/4 thick, tap a hole in it, like 7/16 or half and then locate where you want to put the seat belt holes in the side of the rear shelf. Drill the 9/16 hole there and drill two 1/4 to 3/8 holes on each side of that to spot weld the plate in, you would have to fish it through the hole where the cab bolt goes up into the shelf. Wouldnt be that hard for the outboard ones, but the inner ones you would need to fish it up through with wire or something. This would be the most minimal damgae to the paint and would be an easy touch up with a roller. You could weld a nut to it also.
Back when I did trailer hitches, the chevies (99') had boxed in frame rails so I had to do some creative fishing with wire to get bolts in there and up through the bed or what not. same thing would be done here.

[mightydodge]

Well, what I did was go in through the access points for the cab bolts, those nice rectangular holes on the front of the box under the gas tank. I took the nut-washer combo and duct taped it to a flexible magnet wand. I'm sure that a coat hanger would work too, but you'd have to make sure and curve the end a bit so that it would catch the duct tape when you pulled it out. Then I inserted the nut-washer combo/magnet wand into the box, slid it along the facing of the box on the inside until the nut-washer lined up with the mounting hole for the seatbelt. Then I ran in the seatbelt bolt. After it was tightened and secure, I pulled the rod out which brought the duct tape with it. All done!

Note: I duct taped the nut-washer combo to the rod flat; I did not wrap the duck tape around the sides or edges of the washer. This is why it held the nut-washer combo when I slid it in, but came off easily once the bolt was in and I pulled the rod out. Takes a little practice, but worked out really well, and I didn't destroy my paint!

[steven]

Thanks guys, got some good ideas. I'll probably weld it, it wont be too bad to touch it back up. Especially with rustoleum.

Now, can someone get me some measurements? Please?

[Cageman]

Sure can tomorrow, I have a bare cab, actually two in the shop right now.

[nfury8]

Took a little closer look at mine today, the seats are in so I couldn't feel back in there.
It looks like the threads might be a 3/8" thick plate threaded, rather than a nut.
Hard to tell exactly, but it just didn't look like a nut for some reason.

[steven]

Any measurements guys? Thanks...

[Cageman]

Totally forgot, Ill go get them now.
Sorry. I leave the house I guess my mind goes blank, Ill write it on my hand.

[steven]

zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

[Cageman]

Super speedy delivery is not my middle name, but I got the measurements.
I measured from the edge of the seat mount towards the rocker first. From that edge it is 5 inches to the center of the bolt, that is also 3 inches down from the top of the ledge to center. That locates the drivers side one, then from the center of that bolt it is 21 1/2 inches to the middle one, center, and that one is also 3 inches down to the center. Same for the pass side seat belt holes.
That is what I would do, drill the holes, and make them maybe 5/8 or 9/16. Then make your plates out of 3/8 thick 2x2 or 3.
The middle ones will take some fishing to get lined up, but if you lightly tack weld a piece of small rod to the sid eyou could fish it in there, then since it was tapped for a 1/2 inch bolt, run a bolt up in it and tighten it down. Break the rod off and drill 4 holes and spot weld em in. Repeat.
I take all the seat belts out and thropw em away, LOL they are not the safest or even remotely comfy seat belts. Maybe yours will be nicer. If I doe while driving one of my swepts, I died a happy man. Ill probably choke on a tuna sandwich and die from that.

[steven]

Thanks so much John. Like I said, for now it'll be the two points. I'll put 3 points in later.

[Cageman]

Hood to menomonie, is that close enough?
middle to end of March, soon enough?
My buddy is taking his race car to Jimmy Mars place in meonomoneiemonie. Not sure when, but within the month, he is working his tail off getting his racecar ready to go there. I might go with just to learn from a legend. You may not know who he is, but he is a really fast racer. Either way, he said he has room for the hood.