Not finding any DIY or How To on this. Any way to install Shoulder belts into the back of a Supercab. Preferably all 3 seats. Currently just lap belts and I want to upgrade for when my kids ride back there

 

I used to have a '72 F100. I'll suggest you do a search in the Bump section, '69-'72 as it was a common upgrade for those years since they were pre-shoulder belts. I imagine that will give you a better idea of how it's done and how you can modify it for your supercab.

 

didn't see anything really besides retrofitting for the front of the cab. most in depth I found was mention of removing rubber plugs and then bolting in the setup. thanks for the suggestion

I'm mainly worried about how to put the top-most piece into the cab corners. is there bracing I need to weld in? I can easily re-inforce the floor if needed.

and how do you mount a center setup? My old Superduty had the belt built into seat frame. that would be the easiest part of install I think.


I may just get some square tubing and built a sub-frame that rests behind the seat against cab wall. mount the retractors and upper mounts to that. should negate worry I have of mounting bolts pulling through sheet metal

 

Maybe you could use the belts and associated pieces from a slightly newer truck. I think the first year for rear shoulder belts is 1994, but it might have been a year or so earlier.

 

Find a truck in a pick a part yard & cut out the section of post to put into your truck. I don't think the center rear seat ever had a shoulder belt. Maybe the next generation (1997 up F150, 1999 up S-duty) has the center shoulder belt setup.

 

Careful with retrofitting seatbelts, there is a lot of design that goes into proper safety equipment and if done wrong this can cause more harm or even kill the occupant instead of keeping them safe. This is why there are retrofit kits for older vehicles that may have come with shoulder belts from the factory, because in the early days the analysis was poorly done and modern engineering can do better. Please consider the consequences of this before putting your children in a home-brew shoulder belt setup. I hope I have not offended you but this is a serious safety concern. Also consider the fact that the Supercab structure was not designed for rear shoulder belts and might have other ramifications such as in a roll-over.
Try looking at what the Crew Cabs have for rear seatbelts.

 

Your best bet is probably to :

1) go to the junkyard pull the rear bench out of an OBS
2) pull a middle rear seatbelt assembly from a newer truck
3) mock up the seatbelt assembly up in the back of the OBS and see if it's a good fit
4) if it is not a good fit go to step 2

If you can't find an appropriate crew cab in the JY newer single cab trucks also have middle shoulder belts.



Sure, whatever. Any time safety systems are involved all logic goes out the window, the sky is falling, think of the children, etc, etc. We get it

He's not designing a system from the ground up, he'd retrofitting a shoulder belt to a location that only has a lap belt and in which newer vehicles have shoulder belts.

The basic geometry of a bench seat has changed approximately not one single bit over the last century and change. Adding a middle shoulder belt to a bench that only had a lap belt should be a simple case of finding a factory setup that's dimensionally close, adding the necessary reinforcement and mounting points to the cab and bolting it down. Other than shoddy fab work there's not much to do wrong.

 

That's why I'm here asking instead of blindly forging ahead

the sheet metal on these things is pretty thin, not ideal anchor points for the upper mount for a shoulder mount.

I appreciate the data and ideas. I need to find a Screw truck seat and look at its framing. See about adapting to the Scab seat I have. My Tahoe and old Expy had the seatbelt integral to seat frame. This seems the most ideal setup in terms of ensuring secure mount points

 

I'd blindly forge ahead, assess the result and repeat until desired result is achieved. Since we (as enthusiasts and DIYers) don't really have the capability to simulate how what we build will perform the things we design instead of copy tend to be massively overkill. If you can look at whatever you retrofit and think "yeah, that's got plenty of strength to it and is geometrically equivalent to how it was in the donor vehicle" then it's probably good. On the other hand, my background is 4x4s and my first instinct is to design everything as beefy as possible and only cut back as necessary. If your background is racing and your first instinct is to cut weight wherever possible then tread lightly.

Can we consider the outboard belts solved? Any 94+ extended cab truck should have what you need.

Yes, integral to the seat makes it very easy. If I remember correctly, the bottom part of the 2nd row in the extended cab folds up but the top is static, right?

The floor is the easy part. Find a retractor that fits in the space you have (I have a reg cab so I'm not as familiar with how much space you have but I know it's a lot less, you may wind up having to get a retractor from one donor and the upper guide ring from another)

The lower rear window sill is the hard part. Look at other trucks with a middle seatbelt. They've got thin sheet-metal too. The main difference is gonna be where the seatbelt mounts it's gonna be double or triple thickness (either the same sheet folded over and spot welded or a different sheet die stamped and spot welded in) that are formed to have a lot of strength in the direction a seatbelt would pull. This spreads the load across more of the back wall.

I would go for having at least as much structure as the donor vehicle. The first thing I'd look into would be forming some sheet metal (or cutting something out of a junkyard vehicle) to plate the rear window sill with to add rigidity. You may even be able to fab something that has the necessary features so that you can cut some part out of a donor vehicle and bolt it right in.

The less OE looking but easiest thing would be a simple 1.25x.188 cross tube with flanges that bolt up to a pair of tapped flanges welded to the C pilliar (kind of like a cage)

Now that I'm actually thinking about this I'm rapidly reaching the conclusion that retracting belts are a hassle and you should just run a cross tube and install small aircraft (go-cart) style 4pt seat-belts. They're great for holding cargo as well.

Going from "I'm not very familiar with seat-belts" to picking the right junkyard parts to add 3pt belts to your truck is gonna probably take several tries to get right. Projects like this always do. You'll probably one style of retractor, get 80% of the way through making cab reinforcement, realize you can't get the balance between strength and "not looking like crap" that you're looking for and jump ship for a seatbelt system from a different vehicle.

What do E-series airport vans use for seat-belts in the middle rows?

It's been years since I've ridden in an E-series that was configured to move people and I'm pretty sure I've never ridden in one that was new enough to have 3pt belts in the middle seats.

 

Unless you are putting a roll cage in, there is nowhere practical to mount shoulder belts into the sheetmetal structure