AMC style seatbelts not catching

[Warren99]

Gonna need to address this when I swap my interior but its an 87 chief so it has the AMC style seat belts. I noticed that both do not latch up or catch whenever you yank them forward, or otherwise throw yourself forward like your in a crash. I haven't looked into it at all yet but if theres a common issue or good place to start please let me know, thanks!

[jpnjake]

I’m pretty sure they don’t do that. They should only lock when the vehicle is tilted side to side. Try parking on a side hill and taking out the seatbelt. I could be incorrect but this is my experience with them. 

[Warren99]

Alr I'll give it a try but if that's the case then I don't see how they would work in an accident lol

[jpnjake]

Lol me either. Pretty sure my 2000 xj does the same, and so did my dads old 98xj along with our other MJ’s 

[Warren99]

My 89 MJ locks up fine if you just pull it fast, I tried pulling on this one as fast as I could and it didn't.

[cruiser54]

Clean out the mechanism. 

[87MJTIM]

There is a weighted pendulum that activates the locking mechanism.  Tugging on the belt doesn't always cause the pendulum to move enough to trigger the lock.  You could try parking on a downhill and tugging or driving slowly and step on the brakes.

[Pete M]

new aftermarket XJ belts are available and are close enough to work on MJs.  

[Minuit]

Step on the brakes hard and see if they catch then. The ones in my 91 are original and catch when stopping, but not when pulled.

[Warren99]

These are black and in my donor truck rn so I can't do any real testing until they are in mine. I have some that work fine just they are gray and won't match the back interior I'm about to put in. 

[jpnjake]

Try this. Take the seatbelt that isn’t in the truck and tilt it forward backwards and such. It should lock the seatbelt. There’s a pendulum inside the seatbelt that causes it to lock when it moves. They should only move when you have them close to straight up and down