How to remove and reinstall the front seats without drama and add a little leg room too!

For some reason, Porsche decided to use special socket-head DIN6912 M8X20 screws with shallow Allen heads to mount their seats. This has made seat removal to gain access to the DME, alarm controller, or audio amp a tortured experience for some. The issue is that when unfastening the seat, the cap screws' head socket strips during removal. Below is how to remove a seat with a minimum of this drama:

Removing the seat:

6mm Allen wrench

• First, put a drop of odorless penetrating or sewing machine oil on each of the seats' mounting Allen head cap screws and give it a few days to soak in.
• Do not use PB Blaster or any other acidified penetrating oil, as it will take years to get the acrid smell out of your car! Don't ask me how I know this.
• Raise the seat both front and back to its highest position
• Remove the capscrews that hold the seat down. 

• Be sure to use the right size Allen wrench and fully insert it, holding it square to the capscrews' heads so as not to strip the screws' sockets when releasing them. Using a high-quality Allen wrench may help prevent stripping the head.
• The force applied to remove feels relatively high, and if not previously removed, the capscrews release with a "pop" sound.
• Use high-quality, preferably new, Allen wrenches, as the cap screw heads are easily distorted and can be stripped. Some use a special 6mm DIN6911 hex key bit with a center-piloting provision, pictured below; however, I have never used such a tool.
  
• It may be advisable to have a few replacement cap screws from the dealer on hand to replace those that become gnarled during removal. The issue is that even slightly gnarled ones may be problematic and strip the next time one plans to remove the seats.

• Unplug the seat's power seat and seatbelt warning light pigtails and lift the seat out of the vehicle. The seat is heavy and best removed with the back folded forward, taping some cardboard down to protect the door threshold from scratches if you bump it.

Important reinstallation notes:

• Some of the rail cap screws have two washers under them. This appears to prevent the unthreaded section of the capscrew's shank from contacting the threaded holes in the pedestal or backing plate. Coming in contact would strip the threads, weakening the seat mounting.
• WARNING: The number, thickness, and possibly the hardness of the seat mounting washers differ between the rail front and back mounting positions, so make sure you reinstall them in the same positions as they were originally when the seat was removed.
• WARNING: washers have a top and a bottom. The tops have smooth edges, and the bottoms have sharp ones. When reinstalling the mounting capscrews, be sure to face the smooth side of the washers up under the capscrews' heads to avoid damaging the small fillet under the head, which significantly weakens the capscrew and therefore compromises the safety of the seats' mounting.
• A torque value of 23 Nm (17 ft-lb) should be used for lightly oiled mounting capscrews. Tighten the rear rail capscrews first, then move the seats back and tighten the front capscrews.

Getting a little extra legroom  when remounting the seat:

• If your seat was originally mounted in the forwardmost mounting holes on the seat rail pedestals, you can move the rail back to the second set of holes on the pedestals' frames. At the rear of the rail, the rear threaded pedestal backing plates can be slid rearward to align with the two mounting holes further back. The front holes in the pedestals are both threaded to accept the mounting cap screw. Moving the rails back will give you about an inch more legroom and a little greater clearance between the seat and the steering wheel to get in and out of the car. 

• Beyond this, seat rail extensions, marked in red in the picture below, are available that are placed on top of the seat pedestals, pictured in yellow. Some allow for attaching the seat even further back by

  

  Under Seat View 

  about an additional inch, while others add a small amount of height. They can be purchased from  Porsche-focused aftermarket distributors or easily fabricated from steel bar stock from a local hardware store.

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