What causes a retractable seat belt to lock up during hard braking ?

[Kern Dog]

The belts in the red car were new in 2015. The ones in Jigsaw were new in 2003.
Rear shoulder belts look to be a fairly easy upgrade and at a fair price if you're willing to use something from a junkyard.
the cars we looked at had no heavy collision damage so the belts were probably not stressed.

 

[1 Wild R/T]

You'd be shocked at how much strength seatbelts have... I've used them many times in wrecking yards as a sling to lift engines & transmissions as an assembly....

 

[Kern Dog]

Me too. I currently have seat belts here that are used for lifting engines and axle assemblies too heavy to lift alone.

 

[OneWheelPeel]

You'd be shocked at how much strength seatbelts have... I've used them many times in wrecking yards as a sling to lift engines & transmissions as an assembly....

When I used to go to the JY all the time it was always common to see seatbelts that were cut to make engine slings, as well as carpets ripped out of the cargo/trunk area as something to lay on while working under the junkers.

 

[furious70]

When I was researching I found both kinds of locking mechanisms and I'm pretty sure mine from Andover restraints are just the speed lock type to give me more flexibility when mounting

 

[YY1]

If you look closely at the webbing, it is amazing how many strands and how tightly woven.

BTW- I just examined the "loops" on my wife's hyundai-

They are NOT breakaway or lengtheners.

Just a well stitched loop that's not part of the main belt.

Maybe so an EMT can grab and pull away in order to use a cutter?

IDK, but NOT a breakaway lengthening loop.

 

[Kern Dog]

I was able to slice right through a belt at the junkyard using what people now call a "box cutter".
We called it a utility knife on the job.

I'd guess that emergency response workers have these too.