Distributor Cap and Rotor Replacement

Tools

• 1/8" or 3 mm hex key
• Flat-tip screwdriver with a long, thin blade (see note below)

Note: The factory manual calls for bending a flat-tip screwdriver to a 90-degree angle to access the bottom locking screw. A long, thin-blade flat-tip screwdriver inserted at an angle with the blade resting against the lip of the nose panel (protect the paint with a towel) typically provides better leverage for pushing the locking screw in against its spring pressure.

How the Distributor Cap Locks

The 944 distributor cap is held by two 90-degree locking screws whose tips lock into raised U-shaped tabs on the inside of the front distributor housing cover. The elongated openings in the cover are offset to one side, so both screw tips must point in the same direction to clear the openings. The U-shaped tabs have one leg longer than the other, acting as a mechanical stop — the screws can only be turned in one direction to unlock and must be positioned correctly to insert.

Removing the Distributor Cap

1. Using paint or nail polish, mark the bottom half of the top locking screw and the top half of the bottom screw.
2. Push in on the bottom locking screw and turn clockwise 270°. When complete, the painted half of the screw head will point toward the exhaust manifold side of the car.
3. Push in on the top locking screw and turn clockwise 90°. The painted half will also point toward the exhaust manifold side of the car.
4. The cap should now slide off easily.

Installing the Distributor Cap

1. Hold the distributor cap in its normal installed orientation (one locking screw on top, one on bottom).
2. Turn both screws until the 90-degree tips point to the left (when looking at the front of the cap).
3. Using paint or nail polish, mark the left half of each screw head (the side closest to the tip of the screw).
4. Install the distributor cap. The screw tips should slide easily into the elongated holes in the housing with the cap centered over the rotor.
5. Turn the bottom locking screw 270° counter-clockwise. The painted half will point up, toward the center of the cap.
6. Turn the top locking screw 90° counter-clockwise. The painted half will point down, toward the center of the cap.
7. Connect the spark plug wires to the distributor cap.

Removing the Rotor

1. Use a 1/8" hex key first. If it is too large, use the 3 mm. Do not use the 3 mm on an original (factory) screw — original screws are slightly larger than 3 mm and were installed with thread-locker; the 3 mm key will likely strip the head.
2. Once the retaining screw is removed, the rotor may be very difficult to pull off — it can bond to the camshaft extension. Try twisting it off. If the rotor body breaks (it is brittle Bakelite), the metal sleeve inside can be twisted off the camshaft extension using channel-lock pliers.

Installing the Rotor

1. Slide the rotor onto the camshaft extension.
2. Insert the Allen head retaining screw and tighten (1/8" or 3 mm hex key). Take care not to drop the screw into the distributor housing cover.