40/41 seat belt install

[Sixseven]

I want to install seat belts in my 41 and am not sure where a good attachment point would be. I have the typical rust decay along the back of the cab that I will get around to later so I can't connect to the steel floor with any sense of reliable strength.

Can I get ideas and possibly pictures?

[BABAR40]

Is there anyway to attach angle iron or steel tubing across the back of the cab? Whatever you do, the stability and strength of how that steel is anchored is the main focus. But attaching the belts to any kind of rust is purely dangerous.

[TomT/Williamsburg]

The best way is to go through the floorboard and into the frame rail - the center "X" will suffice for the middle two straps and I have used body to frame bolts wherever I can find them for the outside two belts. Make sure you get belts that are long enough to function with your bolt locations.

[JSeery]

I don't remember all of the reasoning at the moment, but many advise against attaching seat belts to the frame for street driven cars and recommend only body metal. Believe it has something to do with the impact through the frame not given enough as opposed to body metal, but not sure.

[john worden]

I think you want to anchor to the body only so that in a serious wreck if the body were to shift on the frame there would be no effect on the belt tension.

[V8COOPMAN]

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Think about this possibility.......Ol' Bozo comes up behind ya while texting other bozo. You're stopped at a light, and Bozo doesn't see the light. Smashes into your pick-up bed at 30, or even 40. That bed is gonna tear clear of it's few mounting bolts, and it's very likely (with that broad expanse of sheet metal sitting up against the rear of the cab) gonna push that cab forward also (with it's seat bolted to the sheetmetal floor). So, cab AND seat go forward. Seatbelt remains solidly glued to frame rails. What do ya think that might do to your guts? Those belts DO NOT stretch.

This is the main reason even new cars attach seat belts to body structure rather than chassis structures. DD

[JSeery]

Did a little research and there are arguments on both sides of frame vs sheet metal for seatbelt mounting. Sheet metal mounting seems to be the best way to go. A general rule of thumb is to mount the seatbelt to the same surface that the seat is mounted. This sounds like the best approach to me, you want the seat and the seatbelt moving together. Having the seat move and the seatbelt remaining fixed (or the other way around) seems like a very bad idea. Always use some type of reinforcement plate at the seatbelt mounting point.

[Pete]

...

[SofaKing]

Attached is the cab interior of my 39. I too will be adding seat belts. I am thinking that a steel strap, 1/8" x 2" that picks up both bolt holes through the cab floor and in between the seat support. The seat support will add rigidity to the floor structure and the strap will spread the load across a larger area of the floor metal. My expectation is the bolts will still deform the floorboard but not pull through due to the strap in an accident.

[alanwoodieman]

there is a sort of channel iron under the rear of the cab where the body to frame wood blocks are located, plenty of strength along that channel to drill 4 holes for the seat belts, use a large flat washer for strength, may need to trim the washers to fit inside the channel. I have put several sets of seat belts into 40/47 truck cabs using this method. if you would like I will try to take a picture and post later today.

[V8 Bob]

Originally Posted by Pete

......WRONG!!!
The reason is because there is no frame on most new cars....
Attaching a belt to the floor of a vintage car with a washer or small gusset is not sufficient.
As far a the body being dislodged in a wreck, nobody has yet come up with a documented case of that happening.

Have you ever seen a seat, or seat belt, bolted to the frame on a production body-on-frame vehicle? I haven't, and I've been under hundreds over the years. If you know of one, I'd like to know.
As far as bodies being dislodged, I also have seen a few, including a couple of bodies completely separating from the frame. In one case the driver stayed belted with the seat/body for many yards, and lived. If the belt had been attached to the frame, he wouldn't have been so lucky! It does happen.

[40 Deluxe]

Originally Posted by Pete

"This is the main reason even new cars attach seat belts to body structure rather than chassis structures. DD"

WRONG!!!
The reason is because there is no frame on most new cars.
When an OEM seat belt is attached to sheet metal, the surrounding area is DESIGNED for it. It is heavier gauge in the immediate area or is reinforced with gussets or stamped in ribs. The design has also been crash tested with instrumented dummies.
Attaching a belt to the floor of a vintage car with a washer or small gusset is not sufficient.
As far a the body being dislodged in a wreck, nobody has yet come up with a documented case of that happening.

It happened to my wife! About 30 years ago she was driving a '67 Bronco when a rear axle broke and the wheel came off. She hit a huge rock just off the shoulder of the road that was just below bumper height. The body sheared completely off the frame and slid and bounced down the road a ways. My wife, son and sister all survived even though they were not wearing their seat belts (no excuses, but it wasn't the law then). Needless to say we all buckle up ever since!

[V8COOPMAN]

Originally Posted by Pete

"This is the main reason even new cars attach seat belts to body structure rather than chassis structures. DD"

WRONG!!!
The reason is because there is no frame on most new cars.
When an OEM seat belt is attached to sheet metal, the surrounding area is DESIGNED for it. It is heavier gauge in the immediate area or is reinforced with gussets or stamped in ribs. The design has also been crash tested with instrumented dummies.
Attaching a belt to the floor of a vintage car with a washer or small gusset is not sufficient.
As far a the body being dislodged in a wreck, nobody has yet come up with a documented case of that happening.

Originally Posted by V8 Bob

Have you ever seen a seat, or seat belt, bolted to the frame on a production body-on-frame vehicle? I haven't, and I've been under hundreds over the years. If you know of one, I'd like to know.
As far as bodies being dislodged, I also have seen a few, including a couple of bodies completely separating from the frame. In one case the driver stayed belted with the seat/body for many yards, and lived. If the belt had been attached to the frame, he wouldn't have been so lucky! It does happen.

V8 Bob......Thank you for YOUR reasonable, intelligent and common-sense reply. I didn't reply any farther to the rediculous statements above your post because it's impossible to change the mind of a "shoot from the hip-type", closed-minded know-it-all. Besides that, and not counting our old cars, Momma and I drive two current-day daily drivers with full frames, which the confused poster proclaims just about don't exist any more.

Again, the original subject was re: wisdom used with installing belts in a 65 year-old Ford pick-up truck. DD

[TomT/Williamsburg]

Originally Posted by TomT/Williamsburg

The best way is to go through the floorboard and into the frame rail - the center "X" will suffice for the middle two straps and I have used body to frame bolts wherever I can find them for the outside two belts. Make sure you get belts that are long enough to function with your bolt locations.

Did not mean to create a fire storm - since I usually build non-stock stuff with modified Caravan or suburban seats, they all have provision for attaching seat belts and they are on the seat. So, lesson learned for me - do not attach to the frame!

[Ralph Moore]

Seen it happen here, a guy I used to know(since passed) gave his beautiful 1940 pickup to his son, well he wrecked it and not only did the cab shear off the frame, but it caught fire as well. Only by the grace of God did he live through it.
My recommendation, bolt to the body only.

[Pete]

Originally Posted by V8 Bob

Have you ever seen a seat, or seat belt, bolted to the frame on a production body-on-frame vehicle? I haven't, and I've been under hundreds over the years. If you know of one, I'd like to know.
As far as bodies being dislodged, I also have seen a few, including a couple of bodies completely separating from the frame. In one case the driver stayed belted with the seat/body for many yards, and lived. If the belt had been attached to the frame, he wouldn't have been so lucky! It does happen.

You excerpt what you want of someone else's statement to suit your misguided thinking. You would make a good politician.

[47 flatbed]

I think by the sounds of opinions on mounting I'm better off taking my chances with out belts. Chances of a new Prius actually harming me or my truck or any new thin metal vehicle actually making a dent are few and between.

[V8 Bob]

Originally Posted by Pete

You excerpt what you want of someone else's statement to suit your misguided thinking. You would make a good politician.

Pete, please explain my misguided thinking, instead of throwing out more of your BS.

[Marvin/TN]

I know of at least one that it happened to, needless to say the only person in the 34 or 34 pickup died.

[Marvin/TN]

Yeah, but what about that 72 Impalla or full size Olds that are still out there.