I have been wanting to put seat belts in my 4100 since I bought it, but was not coming up with an easy effective way to mount them to the floor, so I simply mounted them to the back of the seat frame with a 51 inch piece of angle iron spanning across the back where the the top, and bottom cushions meet. It keeps the ends of the belts right next to your hips. I know it is not as effective as a 3-point belt, but I figure the seat frame is sturdy enough to at least keep me inside the truck if something bad happened. Plus it will keep the grandkids from sliding across the seat into the door while turning. I used 48 inch lap belts, and will install a center belt after I take the ones out of my 55 Chevy 210 which I temporary installed before I put in 5-point harnesses this winter.
Last edited by 4100 Fire Truck; 09/23/202112:44 PM.
If you're going to use angle iron, put it under the cab floor and drill and bolt Grade 8 3/8" or 7/16" fine thread bolts and big flat washers (3" or so in diameter and 1/4" thick) to pull the angle up against the floor. A bolt around 3" long or so can also be used to attach the seat belt bracket and it will spread the load better than an above-floor angle iron. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Actually I think my method is more than adequate to keep me inside the truck, and held in position to manhandle this truck. Of course then there is the steering wheel, but I like to drive my fire truck like it's on the way to a fire, which is difficult if you can't stay strapped into position. There are many modern cars with belts attached to the seats, and the seat frame in these trucks are probably more over built than most of them. I can't go over 45 anyway, and a great, safe driver.
Last edited by 4100 Fire Truck; 09/27/202110:05 PM.
An impact at 45 MPH with an 180 lb person strapped in will put ~18,000 lb on the seat belt. The seat frame is mounted with 4 each 5/16" bolts thru 19 gauge sheet metal, so that's the weak point. Your angle iron just moves the failure point to the seat frame mounting bolts. The bolts may hold, but the sheet metal may rip out.
Keep your fingers crossed.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
