Why does my seat belt work its way tighter?

[Laser145]

Seat belt in my 76 (3 point belt) works its way tighter and tighter as you drive down the road going over bumps. It's very annoying. Gets uncomfortable and you have to take it off and reset it every 20 min or so.

My 87 doesn't do this, anyone know why?

Cheers

[greg64]

My 77 does the same thing. I have a chunk of rubber that I use on long trips. I jam it between the belt and retracting mechanism slot once I'm buckled in. Keeps it from retracting any further. No idea how the 87 works.

[Titomars]

the 60's and 70's vehicles work on a counter weighted ratcheting retractor. bumps can cause the mechanism to take up the slack. the later more modern retractors work on a friction locking retractor. Personally my 77 does not tighten with driving. It pretty much stays put for me. But I have had 70's vehicles that did that. I used to use those retractor limit clips on them to help stop that behavior while driving.