Rekeying Porsche Locks

Difficulty Level 3

Difficulty scale:
Adding air to your tires is level one
Rebuilding a 911 Motor is level ten

Figure 1:
Typical 914 Door Lock Front

Figure 2:
914 Door Lock Rear

Figure 3:
Tumbler Restraining Screw, Spring and Cam

Figure 4:
Removing Tumbler with Key

Figure 5:
Tumbler Incorrectly Keyed

Figure 6:
Inserting Tumbler Pin into Tumbler

Figure 7:
Lock Rekeying Kit

Figure 8:
Tumbler Pin

Figure 9:
Correct Tumbler Pins in Tumbler

Figure 10:
Correct Tumbler Pins in Tumbler

     The first step is to remove the lock from the car.  This may vary depending upon which car you have.  This article uses the 914 door handle as an example to follow.   For more information on removing and replacing 914 door handles, please see our technical article, "Replacing & Repairing 914 Door Handles." (Coming soon...)  Figure 1 shows a typical 914 door handle.  This one has actually been anodized black by the previous owner of the car.

     Once you have the door handle, trunk lock, or other lock removed from the car, you begin by removing the inner tumbler.  Figure 2 shows the back of the 914 door handle.   Here you can see that there is a small screw that holds the end cam to the door handle.  Remove this screw, the cam, and the inner spring as shown in Figure 3.

     Once the cam, screw and spring are removed, then you can remove the inner tumbler from the door handle.  This is most easily done by inserting a key into the tumbler.  The key that you use does not have to match the tumbler in order to pull it out.  Inserting the key helps to reduce the amount of pressure that the tumbler pins are placing on the walls of the lock cylinder.  With the key inserted into the tumbler, it should easily push out from the rear, as shown in Figure 4.

     Figure 5 shows the tumbler with the key inserted.  If you look carefully, you can see the tumbler pins sticking up out of the lock.  These get stuck in a groove inside the lock cylinder and prevent the tumbler from turning.  Your goal is to swap or replace the tumbler keys with ones that will not stick up out of the tumbler when the key is inserted.

     This next step is one primarily of trial and error.   With your fingers or a pair of needle-nose pliers, remove one of the tumbler pins, as shown in Figure 6.  Becareful not to lose the small tumbler springs that push the pins outward.  These are very small and have a tendency to fall out when you least expect it.  In order to perform the lock rekeying properly, you need a set of replacement tumbler pins.  These pins come in four different sizes, and are labeled 1-4.  Figure 7 shows a typical lock rekeying key complete with a bunch of tumbler pins and replacement springs.  Figure 8 shows a typical Porsche tumbler pin.  The arrow points to where the pin is marked with a number.

    Now, replace the pin that you just removed with a pin that has a different number.  Unfortunately, some of the pins aren't always marked, so you might have to guess at the right one.  Replace the pin in the tumbler, and then insert the key.  The pin should be flush with the top of the tumbler.  If it isn't, then pull out the pin and try a different one.  Repeat this process until all of the tumbler pins are flush with the top of the tumbler on both sides.  Both sides of the tumbler with the pins flush at the surface are shown in Figure 9 and Figure 10.

    When you think that all the pins are correct, check the tumbler in the lock cylinder.  Sometimes the pins can be worn, and look like they will work, but in reality, they don't.  When the lock turns smoothly, then reassemble the cylinder, and reinstall the door handle.

   Well, that’s about it. Unfortunately, as mentioned previously, you need a set of tumbler pins in order to be sure that you will have the correct pins.

     Remember, that your continued support of Pelican Parts assures that these tech articles will remain on the web, and that development of other articles will continue.  If you have any questions or comments about rekeying locks, please drop us a line.

Robert Waple (robertwaple@home.com) adds:

While you have the tumbler apart, it is a perfect time to clean the tumbler and the housing that the tumbler fits into.  I’ve found that on older Porsches, and even my 944, that the grease used at the factory tends to harden a bit.  This causes the tumbler to be hard to turn when locking/unlocking the door from the exterior of the vehicle.  The trick is to use some type of sovent to break that grease up.  Personally I use rubbing alcohol, not too harsh and dries fairly quickly.  Use a small bowl and do all your work in there.  The springs that push the pins out of the tumbler when the key is removed, thus preventing the tumbler from turning in the housing, are small and have an uncanny ability to blend with any surrounding that they’re dropped onto.  You think finding a dropped contact lense is difficult, drop one of these springs on the kitchen counter and you may spend ten minutes looking for it!  Be smart, use a bowl, as the solvent breaks up the old grease, the springs will fall out of the tumbler.  If your re-keying your locks, after cleaning is when you want to perform that particular step.  Afterward you figure out which pins need to go into which notches on the tumbler, pull them all (keep them in order!!) and apply a small amount of new grease to the tumbler.  Work a small amount into each hole where the springs reside.  This helps keep them there while you re-assemble the mechanism.  Also coat the outside of the tumbler and the part of the door handle that the tumbler fits into.  Personally I use white lithium grease.   You don’t want to apply too much, or you’ll be wiping it off your key every time you use it for the next six months.  Slide the tumbler back into the door handle and reassembly everything.  Insert your key and make sure everything works before installing on the vehicle.