Chrysler Stow-n-Go headrest fix

While nifty, the Chrysler Stow-n-Go seats have a running MAJOR design flaw in them.

The whole thing is injection molded out of Polypropylene (PP in an Automotive cab of all things…) and there is a deliberate planned obsolescence item of an approximately 3mm connecting rod from the actuator cam assemblies to the latch mechanism for the seat fold-down.  It's designed to fail over time- and I have an issue with someone making a safety critical detail (Headrest!) be beholden to a $800-1200 per headrest repair item that WILL fail in 2-5 years, give or take.

To that end, I made up a bit of an over engineered part and basically a BOM that anyone with a good printer and a bit of patience and know-how can fix the thing ONCE for a couple of dollars and a bit of their time.

Needed in addition to the printed part:

• 1 M3 8-10mm wood screw, preferably hex socket head.
• 1 M5 x 20 mm machine screw, also preferably hex socket head.
• 1 M5 nylock nut.
• A hand pin-drill chuck.
• A 2.5-2.8 mm pin drill.

Print the model provided using one of several heat resistant materials:

• PA12
• Spin-trimmer line (Yes…) 
• CC3D's 72D TPU

Most everything else will be quite stiff (Oftentimes TOO stiff) or not have the right heat deflection temps to be in the passenger cab.  TECHNICALLY, PP will be barely within the range, but that'd be only something that I'd use if it was all I had at hand- it just is why the thing broke on you and while it's MUCH more robust than the original design, it still FAILED because of that material choice.  CC3D's TPU is a blend…they're not saying precisely what it is, but it's not really, “pure,” TPU.  It's heat resistance is in the right domains (Unlike most other TPUs) and it's VERY stiff while still being flexy- which is kind of what you really want for this part, hence my choice.  Do NOT use regular TPUs here.  They're too elastic and they don't have a good temp range for in-cab either.  (A side note, the build, as pictured, uses CC3D 72D filament.)

PA12 may be a bit too stiff.  PA6 is TOO stiff.  Spin trimmer line that's 3D printable should work well enough.  If you can lay hands on CC3D's stuff, you may want to spend ~$30 for that.  It needs to flex a LITTLE bit and yet be robust on pulling force, which is why I chose that for the design build to fix BOTH of my seats.  Try to print the stuff with 100% infill and 6 wall loops to make it more robust.

Once you've your part printed, it's like the photos show.  First, cut off the 3mm rod and extract the stirrup out of the latching cam- it's in the way, and it's already caused you enough grief in the first place by breaking…  As shown in the headrest pictures, thread the screw through the left hand hole on the part, through the loose 2/3rds hole on the latching cam mechanism and tighten the M5 nylock down until the part is moderately snug on the cam, where it will rotate and float somewhat loosely on that cam.,  From there, flip the part down and over the cam lever (The arm that goes from the left side as you face the assembly with the top of the headrest to the top)  This should allow for the hole on the thin side of the part to overlay the part on the wide rib on the top of the lever.  Once there, take the pin drill and drill a hole in the center of the hole on the printed part, into the rib in question.  After that, screw in your M3 wood screw as it will properly self-tap itself at that point.  It needs to be moderately snug against the part- but don't get it tight-tight.  It will interfere with proper operation.   From there, assemble the headrest assembly back onto the seat, making sure to get the control cable end into the rotating cam's slot and the cable wrapped around the body of the cam on the right accordingly.

At this point, it should just simply work again…like it's SUPPOSED to.  Since it's robust, it shouldn't fail under normal use- and even if it does, you can just print another, right?