CORNHLIO

I think I found out today why my drivers seat sometimes slips back on one side when I lean into it a little harder... I'm fairly certain (outer/upper) hinge is broken. I cant find anywhere that sells hinge parts (other than covers). I could also purchase some local salvage seat and just take it apart for the one piece.
Can someone please confirm this is not what the hinge should look like? (I've compared it to the hinge in the passenger side, and it does not appear different, but I still want to double check).
Thanks in advance.

4-vettes

No I can not confirm as I have a earlier car.
However, advice none the less.
Compare it to the other seat! There are 2 of them in your car. They are identical.

CORNHLIO

Okay, so I took the seat out and figured out whats going on, still would appreciate advice on best course of action.
Im not sure of proper names for everything so excuse my ignorance in describing things...

In the first photo Ive circled where the upper arm of the hinge is supposed to line up to the lower hinge part and stop, however its slipping past and sliding into the middle space in between the 2 lower plates:




In the second photo is how they're supposed to line-up:




Now in the third photo Im trying to highlight the space between the outer lower hinge arm and the upper hinge. This open space is whats allowing the hinge to travel into the wrong area as shown in the first photo.




And finally Im going to include a couple photos of the other side of that joint/pivot point and also of what the hinges look like once removed (found online).





Thanks in advance for any tips/advice, Im thinking a washer is needed, but Im not sure if/how that joint comes apart?
Could I pop in a "snap ring"/ retaining washer?

BarrelCurve

Looks like this ring should pop off if you push it away from the open part. Then, yea, add a washer, reassemble, and see what happens…

67:72

Can't hurt to try! If that doesn't work, you could see if you can bend out that small tang 1/8" or so - maybe do both.

Problem is that the seat frames take a beating because people just fall into the cars instead of lowering themselves. No leg strength? Sitting on the door sill and swinging in would be better than dropping onto the seats. Not the same as your issue, but my '72 had a broken bottom seat frame from this habit; it's so common that there are heavy repair plates for these frames.