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Install a 3 Point Retractable Seat Belt

Project Overview

In this video, Kevin Tetz shows you how to convert from lap seat belts to 3 point retractable seat belts in a 1967-1972 Chevy truck. Kevin Tetz explains the benefits of upgrading to 3 point retractable seat belts, and shows you the tools needed. Then, he walks you through the steps to remove the old lap belts and replace them with the new 3 point seat belts from LMC Truck.

Project Difficulty
Estimated Project Time
3 hours
Required Tools
  • Combination Wrench Set
  • Socket Set with Short Extension
  • Impact Wrench & Sockets
  • 7/16"-20 Fine Thread Tap
  • Screw Driver Set
  • Loctite Threadlocker
  • Safety Glasses
  • Magnetic Caddy
  • Penetrating Oil

Video Transcription

Hi, I'm Kevin Tetz working alongside LMC Truck to bring you some technical information and how-to videos to help you with your restoration projects. In this video we're going to show you how to do a seat belt upgrade from lap belts to a three-point shoulder harness in a 1967-72 Chevy truck. Two-point lap belts were first offered as options in vehicles way back in 1949, but the first three-point seat belt system was available on Volvo's in 1959 as standard equipment. Now, safety belts weren't even required in American vehicles until 1967, and shoulder belts weren't standard equipment on trucks in America until 1977, so chances are you're still running with your factory installed lap belts and it's time for an upgrade.

This is a 3-point retractable seat belt kit that we're going to show you how to install in this ‘72 C10 truck. Two kits are required: one for each side. And, each kit comes with a bunch of different hardware, brackets, and tabs to give you several different mounting options. So, some basic instructions are included with the kit but, we're going to show you details of how to install this in this video.

You can look in the LMC truck catalog or go to to get different seat belt color options and different configurations. And you're also gonna find original replacement hardware if you need it, and things like these seat belts sleeve kits. So, if you're running bucket seats, these will make your seat belts easy to reach.

As far as a scale of difficulty, this one is not that bad. I'm gonna give it a three out of five. However, you are dealing with the vehicle safety system, so you want to be careful and methodical when you do your installation.

Tools that you'll need for this project are pretty basic. You're gonna need a wrench set. I prefer a combination wrench set to give you options; of course, they're SAE sizes. You need a socket set, and get yourself a short extension for reach options. Impact sockets are nice to have around, along with a good impact wrench to really lock something down, like say, a seatbelt anchor or to pull them out if they're really locked into place. Nice optional tool. This is a 7/16 20 fine-thread tap. We're gonna tap out and clean out the threads in the captured nuts in the b-pillars of the truck so we have no trouble with binding or cross threading on our third mounting point on the seatbelts. A screwdriver set is nice to have. Locktite, which you can get from the LMC Truck catalog, is kind of a must-have because you always want to use a little bit of Loctite on your seatbelt anchors when you're reinstalling them. Safety glasses, just common sense. I like these magnetic caddies because it holds on to your fasteners and you keep track of your hardware. A little bit of penetrating oil. Not a bad idea for stuck fasteners. And that's kind of it.

We're gonna move the seat forward so we can get to the back bolts. Now we got really lucky because this truck has been restored recently and these bolts, they're just walking right out of the threads. But if you had original vehicle, there's where your penetrating oil comes in really handy. But for us, they didn't need it. Now, I'll get the front. It helps to have a buddy helping to remove a bench seat in a pickup truck, but it can be done alone. Just make sure you cover the painted surfaces and the doorjamb so you don't scratch them. Here we go.

Nothing was frozen with these seatbelt bolts, but access is a bit of a challenge if the fuel tank is still in the cab on the driver's side. Small hands are helpful but a ratchet and 11/16” socket will get the job done.

So, we know we're replacing the seat belt system anyway. Fifty-year-old safety device… not a bad idea to upgrade it, but let's take a closer look anyway. When I look at the hardware, it's not in bad shape. Threads are ok, a little bit rusty. Ehh ok. This belt, it's alright. It's mildewy and kind of stained, huh, not great, but it's acceptable. This is what really bugs me. It's starting to be frayed here and it looks like it may start to be separating right here at the anchor point. That's unacceptable. This right here, also this is something that we can do better at because there's no lock mechanism for a panic stop. It's gonna fully extend if there's a panic stop situation and we can do better. The new system is brand new. Clasp locks and release buttons. It's got the third point of mounting on the b-pillar of the truck. Safer, and most importantly, it's got a retractor that slides out easily, and under a panic stop, it's gonna lock into place. It's gonna lock you into place in the seating position in the case of an emergency. That's just a better way to go.

If you find yourself in the situation where you have to drill new holes in your floorboards for your seat belt anchors, there's a couple things I want to make you aware of because there is a correct and incorrect way to install a seat belt anchor. Regardless of the type of anchor that you're gonna be using... Whether it's a straight bolt, a tab, or a ring style mount, you never want to just rely on the strength of the bolt along with the sheet metal. Especially with single-walled sheet metal, you want to use the large flat washers that come with the kit. What that does is build on the strength of the bolt and spreads the load to the flat washer itself, which is pinching the sheet metal and makes it much less likely that this will tear through the floor in the event that something bad happens. And when you're looking for a location to place your anchor points, always look for a place where there's a double thickness of sheet metal on the floorboard, if it's possible. It's just stronger and safer.

This is the hardware that was holding in the main seatbelt mechanism in this truck. They're brand new bolts, but I'm gonna replace them. And here's why. If you look at the head of the bolt, it tells you the identification of the strength of the bolt. Whenever you're installing seat belts, you must use a minimum of grade 5 hardware. It's stronger. It's better. It's safer. If you look closely, here's what I'm talking about. If you look at the head of this fastener, there's no markings on it. There's a little tab, but there's no lines on it. That means it's a grade one, or a grade two, bolt. Not good enough for seat belts. This is a grade 5 fastener. The three lines in a triangle pattern notate that it's a grade five bolt. This one, just for the sake of reference, is a grade 8 bolt. There's six lines on it. So, minimum, you've got to use a grade five bolt, if you're replacing seat belts. The good news is that these seat belt kits from LMC Truck have all brand-new grade 5 hardware. So we're in good shape.

Now, this is a bolt-on project because GM had the forethought to put a mounting point in either cab corner the ’67-72 trucks, but we got to get rid of our little plastic plug here, carefully. And you want to save it. I'm just using a flat screwdriver. There it is. We're not done yet. We want to make sure and chase any debris out of the threaded portion of this. A captured nut. And it's a 7/16 20 fine-thread so that's what we have the tap on the tool cart for. And we're gonna go ahead and chase the threads and get us ready. It's good. We're using the blue colored thread-locker here that we got from the catalog. The blue strength will secure the fasteners against loosening under vibration, but will still be easily removable with simple hand tools.

All right, tabs locked into place. Now we can mount the retractor. So, it's a tight fit in here with this fuel tank but there is room because this is a small case. You've got options with your mounting hardware. With the orientation that works best is to put the retractor right here. Gotta have your belts aligned properly so we've got a clear path. This is a nice travel path from the upper mounting point to the retractor. So, here's the belt that goes over top of the occupant. We know that there's no binds there. That's the correct orientation here. The other point is this you don't want to twist up your belt that locks into place behind the retractor. Make sure that everything is smooth, everything is bind free, as this goes over the occupant. We're in good shape here. So that tells me that my tag is right there. That's the correct orientation. Holding that in place and hold it up here. That's exactly where it goes. So, now I can put my hardware through the retractor. I'm gonna put a washer there so it can pivot. Nothing's in the way of the belt mechanism on the barrel in here, so now I can put this to my tab. Lock that into place; get my nut and lock washer on the backside of this and this part of this operation is finished.

The owner of this truck didn't want the middle occupant lap belt installed, but now is the time to do that if you need one in your truck. the part number is 38-2249 with the last two letters notating the color. Ours is BL.

Now this is gonna set in the correct orientation and come up sit on the bottom and be in between the top and the bottom the seat and that means that we're ready to reinstall the bench seat. And so we give it a test. Nicely adjusted. I could lean, I can lean forward, get the ignition key. Lean forward, get accessories. But in a panic-stop, it does what it’s supposed to do. I love it.

Now, with this C10, even though it has the pro classic sport bucket seats on a full-on custom interior, we're still going to be using the same a three-point seatbelt kit that comes from the catalog. We're also going to be using these seat belt sleeves on either side of the inside of the bucket seats, so it keeps that belt up handy and easy to reach for. The way this works is you just feed with the correct orientation. You just feed your seat belt into a plastic sleeve till you see the loop come out the bottom side. Right there. Okay, so now we can put our hardware through and lock it down. If I wasn't using these plastic sleeves, I would simply mount the seat belt like this, run the hardware through, and we'd be done for the inner belt. But I like the look of these and the convenience.

This truck has a fuel tank behind the rear axle, so there's more room for the belt retractors. And you've got more options for orientation. It made sense for us to mount them at a different angle in favor of a smooth and free path for the belt in all directions. We were also able to reuse the original coarse thread bolt anchors in the floor boards since they weren't removed or damaged in the restoration.

That's it. So, with a few hours of your time and some simple hand tools, you can upgrade your truck to a much higher safety standard, and it's gonna look period-correct in your vintage C10.

So, for more information go to, click on the videos tab for more great how-to videos, or just take a look around and see what you can do to customize your truck. See you next time. Thanks for watching.