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-   -   Best 3 point seat belts. Suggestions (https://67-72chevytrucks.com/vboard/showthread.php?t=707263)

blazercrazy70 05-17-2016 12:04 AM

Best 3 point seat belts. Suggestions
 
Looking for some good 3point seat belts. Looking for reccomendations

69chevytrucker 05-17-2016 12:15 AM

Re: Best 3 point seat belts. Suggestions
 
1 Attachment(s)
seats out of a 2000 gm truck is what it did for that same reason wanted the 3 point seatbelt and they are built right in the seat
Attachment 1533756

StingRay 05-17-2016 09:48 AM

Re: Best 3 point seat belts. Suggestions
 
Any seat with integrated belts requires substantial floor reinforcement. Seat belt loads will all get transferred through the seat mounting points that were never intended for such loads. Even a truck that came with stock 69-72 buckets had floor reinforcements that the bench trucks did not. Failure to re-engineer the floor could result in the front of the seat rotating downwards through the floor resulting in you impacting the column. It could even result in you and the seat being ejected from the truck. Your best option is a rust free floor and cab mounts and using the stock engineered mounting points designed by GM for exactly that purpose. The 99-06 seat is a nice seat. I have one in my 04. That's exactly where it belongs.

I guess I should qualify this. Swapping one bench for a more modern one is not a big issue. Attention to how it's mounted definitely needs to given and you generally can't just drill and bolt anywhere you like without evaluating the structure and adding gussets where necessary. The integrated belt stuff is a whole different animal.

Ironangel 05-17-2016 10:26 AM

Re: Best 3 point seat belts. Suggestions
 
I have to agree :rolleyes: with the above. I'm in the process of installing factory 72 buckets in one of my trucks and added reinforcement under the floor for the seat mounts. I used the existing belts in the factory locations that were for the bench seats and they work fine for the buckets. I also added the shoulder belt that has it's own dedicated latch. LMC has the 3-point belts your looking for or you can add another dedicated shoulder belt from another vehicle like I did. The shoulder belt bolt should be a grade-8 NF 7/16 x 1" w/hard washer...~Ghostrider~
http://www.lmctruck.com/icatalog/cb/full.aspx?Page=91 https://scontent-dfw1-1.xx.fbcdn.net...95&oe=57E80936

fwayne 05-17-2016 10:43 AM

Re: Best 3 point seat belts. Suggestions
 
I Just installed the LMC 3-point belts in my '70 with bench. They installed OK, only LMC needs to make better instructions( actually ANY instructions would be nice), and if you still have the tank behind the seat they are a pain to install on that side unless you drill a new hole to relocate the retractor. I was able to use all the factory mounting points.

They look great just like factory, but do have overly sensitive retractors. I assume thats because they have to fit so many applications. You have to put them on a bit slower than say a modern truck or they'll catch. For me not a big deal, I'm already used to it. And since my daughter will drive it, I don't mind a belt works more aggressively.

LMC's Kit does include hardware and re-inforcing washers if you choose to drill new holes. There are other belts on the market, or pull-outs from salvage that many like as well. Like others stated, if you use anything other than the stock mounting points, you must use reinforcements

StingRay 05-17-2016 11:15 AM

Re: Best 3 point seat belts. Suggestions
 
There is no just drilling a new hole. The factory point on the driver side is a large nut welded to the flange of the cab support and you have the thickness of the the cab support and the floor together at that point. A new hole would require a special heavy flanged oval washer made specifically for mounting seat belts. I design seat and belt installations as a part of my job and have for nearly 20 years. We destructively test this stuff. I've never failed a test yet so I guess I have pretty good instincts. The stuff I see done in the armature Hot Rodding community usually scares the crap out of me. Often the improvement in seat and belts is more dangerous than what the vintage vehicle came with.

davepl 05-17-2016 01:57 PM

Re: Best 3 point seat belts. Suggestions
 
1 Attachment(s)
Here's mine, from LMC. Everything said about about the install is true.

If you have to drill the additional hole, as I did, I drilled it through the seat frame support so there's multiple layers and plenty of steel. I'm not an expert like SR above but my instincts tell me the hole I added is as strong or stronger than the factory ones. Hardened washers to avoid pull-through, all of that. I sent photos of the bracing and stuff to another member but can't locate them at the moment.

I don't leave them out like this all the time of course, just for the picture. When not in use they disappear for the most part.

flashed 05-17-2016 02:27 PM

Re: Best 3 point seat belts. Suggestions
 
I used Morris Classic belts ,not cheap but made in USA and good quality and bolt in factory locations .

StingRay 05-17-2016 03:02 PM

Re: Best 3 point seat belts. Suggestions
 
1 Attachment(s)
The problem with washers is the sharp edge. Hardened is worse. In an impact the washer cuts and button holes through the steel. The softest most deformable washer would best if a flat washer is used. I would stack a smaller and larger diameter washer so that the outer dia. of the large diameter has the opportunity to deflect, deform and perhaps cut in less. The attached pic is the RV industry standard for a reinforcing washer in seat belt applications. Even it is not a guarantee. Best practice would put it near other structure or stamped shape and where there are multiple layers of material. The radius flange allows the washer to deform and stretch the floor without cutting. Poorly applied even they will pull through.

69chevytrucker 05-17-2016 09:14 PM

Re: Best 3 point seat belts. Suggestions
 
Quote:

Originally Posted by StingRay (Post 7595907)
Any seat with integrated belts requires substantial floor reinforcement. Seat belt loads will all get transferred through the seat mounting points that were never intended for such loads. Even a truck that came with stock 69-72 buckets had floor reinforcements that the bench trucks did not. Failure to re-engineer the floor could result in the front of the seat rotating downwards through the floor resulting in you impacting the column. It could even result in you and the seat being ejected from the truck. Your best option is a rust free floor and cab mounts and using the stock engineered mounting points designed by GM for exactly that purpose. The 99-06 seat is a nice seat. I have one in my 04. That's exactly where it belongs.

I guess I should qualify this. Swapping one bench for a more modern one is not a big issue. Attention to how it's mounted definitely needs to given and you generally can't just drill and bolt anywhere you like without evaluating the structure and adding gussets where necessary. The integrated belt stuff is a whole different animal.

my seats are held down with 8 grade 8 bolts and the floor is solid and steel plates put under the floor you would go nuts if you new my 69 cab is on a 83 k5 blazer frame lol

davepl 05-17-2016 09:25 PM

Re: Best 3 point seat belts. Suggestions
 
Quote:

Originally Posted by StingRay (Post 7596229)
The problem with washers is the sharp edge. Hardened is worse. In an impact the washer cuts and button holes through the steel. The softest most deformable washer would best if a flat washer is used. I would stack a smaller and larger diameter washer so that the outer dia. of the large diameter has the opportunity to deflect, deform and perhaps cut in less. The attached pic is the RV industry standard for a reinforcing washer in seat belt applications. Even it is not a guarantee. Best practice would put it near other structure or stamped shape and where there are multiple layers of material. The radius flange allows the washer to deform and stretch the floor without cutting. Poorly applied even they will pull through.

Not to doubt you, but the LMC kit comes with Grade 8 washers - that's what I meant by "hardened". I figured I should stick with the hardware they supply.

Ironangel 05-18-2016 12:48 AM

Re: Best 3 point seat belts. Suggestions
 
StingRay is correct reguardless of what the Chinese retailers may sell. If you look at the design of the seat mounts under the floor pan you'll notice the nuts are welded to thin channels with rolled edges? When a hole is punched through a piece of A-36 mild steel, a "hardened" die is used...LMC is a retailer, not an automotive engineering outlet..."just sayin!"

StingRay 05-18-2016 09:38 AM

Re: Best 3 point seat belts. Suggestions
 
Quote:

Originally Posted by davepl (Post 7596619)
Not to doubt you, but the LMC kit comes with Grade 8 washers - that's what I meant by "hardened". I figured I should stick with the hardware they supply.


Really! You'd trust your life and those you love to LMC? Do they answer to NHTSA and Transport Canada? I do. Ask them if their installation package is tested and get them to provide documentation. It all seems so simple and logical until you watch simple and logical fold up and fall apart in a pull test. In my teenage days I too bolted buckets into my Chevelle with basic washers and bolts. I get why most think the way they do. Experience has taught me to know better.

The last pull test we did we lifted the back of the vehicle off the ground while pulling the belts. That's pulling forward at and angle about 15 degrees off horizontal and on a 3500 series van. If you think what a seat belt is required to hold is trivial think again.

As I said before seats themselves are not rocket science. The loads they and their mounts are required to withstand aren't that great. When the belts are integral it's a whole different ball game. I specifically avoid doing the same thing because in a retrofit environment the hurdles are generally more than practical to overcome. Belts by themselves aren't even bad when you understand what you are up against and have the benefit of seeing that with your own eyes. The stuff I do that passes the tests often significantly damages the vehicle structure when tested. It's a real eye opener to see a mounting point permanently deflect 3 or 4 inches and I'm generally known for significantly overbuilding my stuff.

Whenever this topic comes up I chime in with same broken record stuff and I get a lot of the same doubt about what actually needs to be done. Ive designed and tested dozens of installations over almost 20 years. Take it or leave it but the best belt installation you can do will use the factory mounting points in the 67-72 trucks. Integrated belt seats are application specific and are a poor choice for this application. Can it be done? Yes. I could do it and feel comfortable with the results and be confident that it would meet the burden of the test. Would I do it? NO I would not.

BluTrukker 05-19-2016 11:46 AM

Re: Best 3 point seat belts. Suggestions
 
X2 on the Morris belts. They are a bit pricey, but they fit perfect in the stock locations and work and look awesome

davepl 05-19-2016 12:02 PM

Re: Best 3 point seat belts. Suggestions
 
1 Attachment(s)
Geez guys, that's why I said "Not to doubt you", I used the hardware in the kit. I didn't say "You're OK, but I'm going to use the hardware in the kit anyway". It was a year before this thread.

I went through some substantial metal - the entire underfloor bracing for the seat mount itself - you could easily lift the truck by it and shake it, if you were strong enough.

Here's a quick pic from underneath. I doubt it could pull through the seat bracket, floor, and top bracket, but I'm not an expert. I used the two step washers as described earlier. If I had it to do over again, I might go one more softer washer if I can fit it in that channel.

Otherwise, how does it look from Saskatchetoon?

Harpie 05-19-2016 03:22 PM

Re: Best 3 point seat belts. Suggestions
 
purchased mine from ebay as a kit I like them fit was good all hardware worked as it should and installed easily.

http://i1257.photobucket.com/albums/...DEB4FD9466.jpg

jeffahart 05-19-2016 08:35 PM

Re: Best 3 point seat belts. Suggestions
 
Quote:

Originally Posted by StingRay (Post 7597072)
Take it or leave it but the best belt installation you can do will use the factory mounting points in the 67-72 trucks.

StingRay/Seat belt man, what are you running, can I see your setup.

I am running factory lap replacements on my 70. I actually purchased the three point and laps simultaneously. When they arrived I chose to keep the factory laps and sent back the three point. The three points felt cheesy. But, I will say, I would have mounted them hook or crook if they would have been a quality item.

Back in the day, no one wore seat belts. The big buckle up for safety campaign back in the 60s and early 70s was to keep people in the vehicle. My great grandfather had been thrown form vehicles twice in wrecks. Then we all stated buckling up... fast forward... my sister ran a red, in my dad's 69 XL GT, after an angry fight with her boyfriend. She was 16 she was wearing a lap belt and bit the steering wheel hard; and lost a few front teeth, she was lucky!

Man seat belts airbags and crumple zone sure have come a long way.

I still tell my wife to buckle the lap in the 70 because I don't want her falling out the door! She tends to get in and lean against the door to face me to talk.

69chevytrucker 05-19-2016 08:47 PM

Re: Best 3 point seat belts. Suggestions
 
well i will have to say that the way i have my 2000 silverado seats in my 69 i feel much safer then i would with the 69 factory seat and lap belt they just started doing seat belts in the 60s so to me modern seats modified are still going to be alot better then ones for the 60s.
just my opinion
we could go all day about the diff mods guys do and if it is safe or not but lets not..

davepl 05-20-2016 11:57 AM

Re: Best 3 point seat belts. Suggestions
 
Quote:

Originally Posted by davepl (Post 7598221)
I went through some substantial metal - the entire underfloor bracing for the seat mount itself - you could easily lift the truck by it and shake it, if you were strong enough.

Otherwise, how does it look from Saskatchetoon?

BTW, I'm from Saskatchewan, so I can use that material.

I'm actually wondering about my math on the "lift the truck" comparison, since I would if I saw someone else post it... If you weigh 200 pounds you'd only have to pull 20Gs against the belt to make that force, and that's easily survivable I think!

Pillow 05-21-2016 09:09 AM

Re: Best 3 point seat belts. Suggestions
 
Subed

mjewett 05-21-2016 08:36 PM

Re: Best 3 point seat belts. Suggestions
 
5 Attachment(s)
Hi all,

Not to hijack this thread, but it's just too timely. I've been looking to get rid of the factory lap belts in my 71 for years so my son can come along from time to time, but never could pull the trigger on an aftermarket set since all the ones I'd seen in other applications looked nice but had super cheap-feeling webbing. Also, I've been thinking harder and harder about selling for something with 4 doors (or at least 3!) for the family.

Last week, I stumbled across a set of matching tan belts out of (I believe) a 1978 suburban. These have much larger retractor assemblies than our trucks and have an angled base mount that does not match the floor near our mount point. However, the set is complete out of an un-wrecked truck, has no apparent damage to any of the components (other than the brittle plastic trim), and the guy only wanted 50 bucks for the set. So I bit, and they cleaned up pretty well.

I have also been wary of punching new holes in the floor and also was not happy using a piece of flat steel or an angle bracket to move the retractor forward, as I have seen others do.

My solution for now, which took me about a half day to conceive and install, was to use a piece of 1/4" angle iron sandwiched between the floor and the rear bench seat mount. I drilled holes in the angle iron so the seat bolts go straight through under the truck. All the original bolts were replaced with new Grade 8 bolts and washers. I actually got longer bolts than stock, threaded the all the way in, and added another flat washer and hex nut under the truck just to cover the up and make sure I could crank everything down super-tight. The shoulder harnesses are mounted in the stock locations with Grade 8 bolts as well.

Here is where I ask all of you to tell me just how poorly-engineered this is and why I should just buckle down (pun fully intended) and spend the cash on an aftermarket set that mounts where they're supposed to. I've attached a gang of pictures so you can see how I set this up. The first 3 pics show the passenger side installed and complete, the 4th pic shows the driver side bracket mounted without the belt retractor (exposed hole in the angle iron will mount the retractor). It's obviously not the cleanest-looking install and I'm still not really convinced this is a safe or appropriate way to go, but it seemed sturdier than the flat steel/angle bracket extension off the factory mount that I've seen before. If someone with more know-how or experience than me thinks this is a decent solution, I'll roll with it for now.

Thanks in advance from a longtime reader who is greatly indebted to this forum as a fantastic resource since I bought my truck.

-Mike

Attachment 1535136

Attachment 1535137

Attachment 1535138

Attachment 1535140

Attachment 1535141

wbc409 05-21-2016 11:31 PM

Re: Best 3 point seat belts. Suggestions
 
if you are dead set on using those belts, I am not sure that the angle iron you are using has enough surface area for the bolts and washers you are using to hold the retractors in place. I would also try to tie that mount into the factory mount by welding another piece of angle or square tubing to the angle iron. If your mount is only held in with the one bolt you could have the angle iron spin under load no matter how tight you have it.
At a minimum I would put a second bolt through the angle iron to prevent it from spinning forward in the event of an accident.

mjewett 05-21-2016 11:36 PM

Quote:

Originally Posted by wbc409 (Post 7600805)
if you are dead set on using those belts, I am not sure that the angle iron you are using has enough surface area for the bolts and washers you are using to hold the retractors in place. I would also try to tie that mount into the factory mount by welding another piece of angle or square tubing to the angle iron. If your mount is only held in with the one bolt you could have the angle iron spin under load no matter how tight you have it.
At a minimum I would put a second bolt through the angle iron to prevent it from spinning forward in the event of an accident.

Thanks, WBC. The angle iron does have 2 bolts, both seat mount bolts are run through the the angle iron. The flange on the iron is wide enough hat the washers don't overhang. I do like the idea of taking another piece and attaching to the factory belt mount hole, but will need to figure out how. Thanks for that suggestion.
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