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  • Repairing a Jeep JK Seatbelt Retractor

    A week or so before the 2014 WFTW event I discovered my passenger-front seatbelt would not pull out of the retractor. I called the dealer and they told me it probably would be covered by my extended service plan but they had no openings for 2 weeks. That left me with a dilemma: I could either ratchet-strap my passenger into the seat or try fixing it myself. Since I wasn't absolutely certain about the safety and liability issues surrounding use of ratchet straps as occupant safety devices, I decided to try and fix it myself.

    WARNING! The seatbelt is a critical occupant safety device designed and manufactured to precision specifications. Any dis-assembly and reassembly, regardless of care taken, can cause the seat belt to not operate as intended, which can lead to injury or death. The descriptions, explanations and procedures described herein are strictly for informational and entertainment purposes only. Neither the author nor this site accept any responsibility or liability for injury, death or damage caused by attempting these procedures.

    Sorry about that, but it had to be said that if you mess with your seatbelts you or your passenger can die.

    This deals with the front seatbelt. I have no idea how the rear seatbelt works but assume it's similar in design, just different to remove from the vehicle. Note that it's also a good idea to wrap some duct tape around the seatbelt so that, after it's fixed, the belt doesn't get sucked-in to the retractor so far that it won't come out, forcing you to take the darn thing apart again.

    For the front seatbelt you'll need to move the front seat forward to get room to work, then remove the plastic trim from the B-Pillar. There are some exposed plastic fasteners to pull and some hidden clips. Once the entire trim is removed there's a Torx bolt holding the the upper slide to the B-pillar, another that holds the retractor to the lower B-pillar, and one last Torx bolt that holds end of the seat belt to the seat. There's also a wire that plugs into the Jeep's wiring harness that needs to be disconnected. Take the entire thing to your bench.



    On the back side (sorry, forgot to take pics) there's a nearly identical white plastic cover, except this one is held in place with three Torx head screws, and has a small slot just outside the center dimple. The slot is used to lock the wound clock spring inside so it doesn't unwind when removed from the retractor frame. Anyway, if your problem is that the seat belt won't retract, then that's the part you need to remove and replace. The spring is a sealed unit and, since I wasn't having that problem, I didn't check to see if it is replaceable separate from the entire mechanism. Of course I didn't realize any of this until after I took it off. Then, since removing the spring housing gave me some wiggle room, I spent 15 minutes poking and probing and inspecting the assembly to see what was keeping the belt stuck. Eventually I decided that the problem was on the other side and reattached the spring housing.


    If your seat belt retracts but does not unlock so you can pull out slack to wrap it around you, the side you see facing the camera above is the side you need to open. Instead of screws there are three plastic rivets you need to push through from the back. A small punch or Allen key does the trick.






    Once all three rivets are removed you can pry the white plastic cover off with a flat-head screwdriver. Inside you'll see a blue plastic gear with a spring-loaded, orange plastic arm inside, and then a rectangular-ish housing in the corner with a large ball bearing in some kind of frame with a hinged cup/pawl deal attached.



    As you can see, there's a fair amount of gunk (highly technical term) on that ball bearing. There was even more gunk glued in the components around the ball bearing. All this is interesting, but I still couldn't see the problem. I removed the blue plastic gear. BTW, be somewhat careful when you remove the gear. There's a spring on the bottom side that you don't want to loose. The pic below shows where the spring should go, but when I took out the gear the spring fell out separately.



    Then you can go ahead and remove the small housing that holds the ball bearing contraption. There's two clips on the back then just push it out the front.



    Here's what it looks like disassembled:

    Mark______________________________________________ _________
    Silver 2010 JKUR | 4" Lift | 37" KM2 on TrailReady's | Full Skids | Winch | More...
    facebook | youtube videos | 2017 Days Wheeling: 10 | Nights Camping: 8


    "The trail was a 5+ and our rigs were rated a 1" -- Evan (LIORClub)

  • #2
    Ok, now I've got it apart, but aside from the gunk and crud (more technical terms), I'm still not sure what's wrong. I spend another 15-20 minutes playing around before I figure it out. Look at these two pics.





    On the left, the bit inside the red outline is the locking pawl. When that is in the extended (outward) position, it engages against the teeth in the frame so the seat belt is locked from extending. This is what keeps you from going through the windshield during sudden deceleration. Notice the pin sticking up from the pawl, and then look at the pic on the right. That red box is around an curved slot in the plastic gear. The pin from the pawl slides in this slot to move the pawl in-and-out.

    Now let's look at this pic again, specifically the Inertia/Angle Sensing thingamabob.




    See the hinged cup with the finger on the ball bearing? Now remember, this pic shows the entire mechanism lying sideways. Usually that ball bearing thing will be on the bottom with the seatbelt facing straight up. When that happens the ball bearing is supposed to fall down to the bottom of its plastic frame, and the cup with the finger is retracted so the finger doesn't contact the plastic gear. This is what I refer to as "normal" position. During sudden deceleration, or if the angle of the Jeep becomes too extreme (such as during a roll-over), the ball bearing moves up and presses that cup out, so the finger engages the teeth in the plastic gear.

    When this finger on the cup is engaged the plastic gear can only spin clockwise. If you pull on the seatbelt, the spool it's attached to, and that's ultimately attached to that plastic gear, spins counter-clockwise. As the spool turns slightly counter-clockwise but the plastic gear unable to turn, it causes the pin on the locking pawl to slide up the curved groove in the plastic gear, causing the pawl to move out and engage the teeth in the metal frame. That is what locks the seatbelt during an accident or hard stop.

    The orange plastic arm and springs on the plastic gear pre-loads the gear in the counter-clockwise direction, so if the finger on the cup isn't engaged, the locking pawl gets retracted and unlocks the spool so the seatbelt can be extended.
    Mark______________________________________________ _________
    Silver 2010 JKUR | 4" Lift | 37" KM2 on TrailReady's | Full Skids | Winch | More...
    facebook | youtube videos | 2017 Days Wheeling: 10 | Nights Camping: 8


    "The trail was a 5+ and our rigs were rated a 1" -- Evan (LIORClub)

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    • #3
      So now I've figured out how it's supposed to work. The reason why it's not working is because all the gunk and crud on and around the ball bearing is not allowing it to fall down all the way and disengage the plastic finger from the plastic gear. I spent a few minutes cleaning the ball bearing, cup and all the bits and pieces with some WD40 and cotton swabs until they were nice and clean. Then I reassembled everything. Note that the spring on the back of the plastic gear has to go into the channel on the seat belt spool, as shown below. This takes a little finesse.



      Now do some bench testing. With the retractor mechanism oriented straight up, as it would be mounted on the Jeep, the seat belt should extend and retract freely. However, if you tip the mechanism left or right more than a few degrees, the belt will lock so it can only retract, not extend. Do this a few times to make sure everything is working. Then reinstall the seat belt mechanism in the Jeep. Remember to put some blue thread-lock on the bolts.

      Finally you should do a dynamic test. Get in the Jeep and make sure the seat belt extends and retracts normally. Then buckle-up and go for a ride. Get the Jeep up above 35 MPH and lay hard into the brakes. The seat belt should lock to keep you from coming forward in your seat. As for testing the roll-over protection function, the best that can be done is to find a hill you can park on at an angle, though I don't know what angle is needed to trigger the locking mechanism.

      Now, even though your seat belt appears to be working properly, there is no way for you or I to know whether it is safe and reliable. So replace this seatbelt assembly ASAP to ensure you have a proper working occupant restraint in the event of an accident.
      Mark______________________________________________ _________
      Silver 2010 JKUR | 4" Lift | 37" KM2 on TrailReady's | Full Skids | Winch | More...
      facebook | youtube videos | 2017 Days Wheeling: 10 | Nights Camping: 8


      "The trail was a 5+ and our rigs were rated a 1" -- Evan (LIORClub)

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