If your door has ever banged you in the shin because it won't stay open on an incline, then maybe you need new door stops. The door stop serves at least three functions:
- prevent door from opening too far, which would damage body parts (yours or car's)
- provide a cushion at the end of travel when the door is fully opened - act as a detent to keep the door open
Replacing the door stops itself is not that hard, it's just that you need to remove the door panels to do it. Here's what I did on my '86.5:
1. Remove door panel (well documented by others).
2. Place a large soft object in front of the door to prevent it from swinging forward and causing damage. I opened the door fully, then placed a chair in front of it.
2. Remove one 5-mm allen-head bolt holding arm of door stop to frame. Be sure to remove tension from this joint by moving the door.
3. Remove two 5-mm allen-head bolts holding door-stop assembly to door. Although these bolts are recessed about one inch, they are easily removed using an appropriate extension and u-joint. I used a mirror here because it's difficult to get your head into a position to actually see the bolts. You can gauge the difficulty of this even before you remove the door panels.
4. Reach your hand into the door and pull out the door stop. You may need to peel back plastic moisture barrier.
5. Install new door stop using reverse procedure. Note that the "arm" of the door stop curves, so the replacement must be installed in the correct orientation. I would describe the arm as curving inward: from the door, the arm curves away from the car, then curves back toward the car to the fitting on the frame.
6. Re-install door panel.
7. Grease the arm of the new door stop.
Note: I noticed what may have been blue Loctite on the bolts, but I
didn't bother to re-install with any. I did, however, use grease on
the non-threaded part of the frame bolt on which the arm pivots -
you'll see what I mean when you do it.
Note: I have not torqued my bolts down yet. If I don't find a torque
value specifically for the door-stop bolts, I'll look up the nominal
torque recommendation for a bolt with about 5-mm width.
Note: Each new door stop (Tuerhalter in German), PN 928.537.033.04, is
about $30 each, and is the same part for each side.
Note: After installation, I now have three (or four?) positions at
which the door will remain open. This detent mechanism requires more
force to open and close the door, however, which is why you'll want to
take the opportunity to repair any cracks in the armrest and shore up
the armrest fasteners with larger washers (another subject).
Thanks to Dave Szewczykowski for prompting me to document my procedure.
The door stops are shock mounted to door. The mounting is between the door and a rubber washer located inside the door interior. The mounting screws compress this washer, thus the locktite.
You won't find a torque value, and I'm sure that Porsche never used this type of wrench when your car was built at the factory.
For a proper installation, you should have roughly 25-50% compression on the washer. I recommend that you replace the washer with a new stop install, your old one is probably shot. It mount inside the door with self-adhesive backing. Cheap part too.