Front Seat Lumbar Bracket Repair (700 series based)
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Lumbar bracket repair notes

  • Inevitably, the chintzy plastic bracket setup used for the 700 series breaks.  The Brickboard FAQ offers several nice fixes that are well worth a look at, including instructions on how to pull up the seat cover to get at the mechanism.  
  • Basically, there is a large while plastic 'bolt' with a rectangular hollow base that houses a metal pin. The lumbar strap mechanism operates through this pin.  The black adjuster knob you turn to adjust the lumbar support pulls this bolt/base affair .  The resulting stress on the plastic causes it to break at the bolt base where it joins the rectangular base.  The fixes on the FAQ entail using some sort of metal bolt to reattach the plastic bolt to the base.  But if the plastic base is broken you need a plan B.  
  • Plan B: make your own rectangular base and bolt it to the plastic bolt.  Construct a base out of some scrap metal plate as per the image below.  I used aluminum.  Note that the pin is an interference fit so drill the pin holes on the small side.  Work up to a hole such that the pin can be tapped in place and is snug.  Drill a hole in the base of the plastic bolt and thread a metal bolt through it and the rectangular base as shown.  I used a carriage bolt that had a thin head so that it did not interfere with the pin.  Cut the bolt to length so that it does not interfere with the stroke of the black plastic adjuster knob (just visible in the last image).   You could reverse the direction of the metal bolt as long as the head is small enough a diameter so it does not interfere with the black plastic adjusting knob.  
  • As they say, assembly is just the reverse of disassembly.  
    RectangleBefore After Done