Seatbelt Saga

UglyDuck

TJ Enthusiast
Original poster
Supporting Member
Joined
Dec 10, 2021
Messages
404
Location
Goodyear AZ
Ok I know it’s not a new topic, but here’s my experience with it.

Going through my new to me TJ, one item of emphasis is safety, which brings me to the seatbelts. For the purpose of this discussion, I’m only referring to the front two, as I have yet to do anything with the rear seat yet.

One of my first inspection items was to test out the inertia reels. I.e. the locking mechanism that stops you from eating the dash or windshield in a collision. Easy enough, pull hard and fast to simulate abrupt deceleration and it should lock.

Driver side, check, no issue.
Passenger side, pull hard, no lock. Attempt several more times, same thing, it just feeds more belt.
That leaves me fairly disenchanted so I turn to the interwebs and find there is a ball mechanism inside that locks in unusual attitudes but releases when vertical.

So I decided to removed both seat belt and give them a good old fashioned cleaning, and rejuvenation.
Basically, clean the 20 years of dirt and grime from the webbing and the mechanicals, without disassembling it. I’ve done this before, usually soaking in mild soap and water does the trick.
So I removed the passenger side and first thing I encounter is that it retracts to its full capacity and locks, with no signs of unlocking, regardless of anything I try to unspool it.
Back to the interweb I go for more knowledge on the subject.
I find that it has to be perfectly vertical to unlock, yet this is not having any effect in my case.
I spend oh about 30 min playing with it until I get it to disengage.
I unspooled it completely and then used a clamp (hemostat) to prevent it from retracting again.

In a solution of warm water and dishsoap, I throughly clean the webbing and mechanism by soaking and scrubbing. I then thoroughly rinse with clean water and dry using compressed air and a towel. Then hung it to dry. The rest of the way. While it was drying, I used the same process on the driver side belt.

Once dry, I removed the clamp, and let it spool up. Then attempted to unspool it. Now it functions perfectly. It locks when pulled hard and fast, releases with ease when vertical, and locks in any unusual attitude (anything other than vertical).
The results are repeatable. I’m feeling good about the seatbelt once again.
Same thing for the driver side, although I notice it has a slightly different design, as slightly stronger return spring.
Looking at the manufacture date, I find a code that, but notice it’s not clear what the date was. Maybe 2011, but that doesn’t make a whole lot of sense for my 2002 TJ, unless they were replaced, but if that was the case, why are they different from each other?

So while I’m at it, and they’re drying, I remove the buckle as well, and give them the same treatment, as they too are sticky with dirt and dust. After a thorough cleaning and drying, I used a squirt or two of triflow (lubricant) inside to assure free movement and corrosion prevention.

A quick bench test with the buckle into the release mechanism returns excellent results, the operate like new. No sticking or jamming. Just easy in and out.
Fantastic.

So I re install the belts back into the vehicle, and prepare to be amazed with the newfound ease and reliability.

First side I test is the passenger belt, which caused me to go down this rabbit hole in the first place.

Same test, pull hard and fast to engage the inertia reel, simulating a crash or abrupt deceleration.
IT DOESNT LOCK.
What in the actual heck!?
Several more attempts, same thing. I just spools until no more belt is left to give.
I know it was working perfect in all possible manners on the bench.
Now once mounted up in that “perfectly vertical position” it won’t lock.
I’m certain it will lock if the jeep is rolled or at an angle, but would it do it’s job in a collision? Probably.
Maybe. But do I really know for sure; no idea.
Driver side totally behaves the way I would expect.

Sorry for the long winded post. Hence the title Seatbelt Saga.

D62B8BFD-CA63-47C0-92B2-7D50BCFB8523.jpeg


0A8CD326-F366-47A0-9161-9E533A1A3078.jpeg
 
I have the same issue on my 95 and 91 but not the 98. The 95's DS would not lock up, the 91's are about as annoying as can be where they seem overly sensitive. If I try to slowly and gently move forward to check something like an intersection or trail change/debris it locks up and your pinned against the seat where you can either blindly run the intersection or stop and F with them till you can see. Im installing manually adjustable/lockable lap belts only and screw these auto POS'es. If you want to keep the OEM ones well like everything else Jeep.....just empty every pocket.
 
The TJ's seatbelt mechanism is an inertia type locking mechanism but not the type that locks with a quick pull of the belt. There's a steel ball in a cup that locks it when it rolls out of the center of the cup from an impact or if you're on a steep climb or descent.

So just because it won't lock when you jerk on the belt is no indication of it being bad or faulty, it's not.

Seatbelt-locking-mechanismE.jpg
 
The TJ's seatbelt mechanism is an inertia type locking mechanism but not the type that locks with a quick pull of the belt. There's a steel ball in a cup that locks it when it rolls out of the center of the cup from an impact or if you're on a steep climb or descent.

So just because it won't lock when you jerk on the belt is no indication of it being bad or faulty, it's not.

View attachment 296912
So why does one “test” fine when installed, the other doesn’t react the same way? Also the one that doesn’t pass the “test” while installed, passes the same check when not installed, but held in the same position?
It sure doesn’t instill confidence.
 
So why does one “test” fine when installed, the other doesn’t react the same way? Also the one that doesn’t pass the “test” while installed, passes the same check when not installed, but held in the same position?
It sure doesn’t instill confidence.
It's a simple mechanism, and it is designed so it will only function properly when installed in its normal vertical position. If it doesn't lock when the ball is out of the center of its cup it's defective. Just stop looking for it to lock when pulling rapidly on the belt, it should not and it won't when it is operating as designed.
 
It's a simple mechanism, and it is designed so it will only function properly when installed in its normal vertical position. If it doesn't lock when the ball is out of the center of its cup it's defective. Just stop looking for it to lock when pulling rapidly on the belt, it should not and it won't.
Fair enough, but the question remains, why does one and not the other? That aside, the one that does, appears to be an “updated” design.
 
Fair enough, but the question remains, why does one and not the other? That aside, the one that does, appears to be an “updated” design.
Maybe, but my '04 TJ's seatbelt works the same way as my '97 did. No amount of belt pulling will, or is supposed to, lock it.