Sunroof Slip Clutch Adjustment

Overview

This procedure explains how to adjust the sunroof slip clutch on a Porsche 944 with a 16v engine. The slip clutch controls the torque applied to the sunroof motor, preventing damage if the sunroof encounters resistance (e.g., when fully open or closed). Proper adjustment ensures smooth operation and prevents the sunroof from slipping prematurely or binding. This guide is specific to the late-model sunroof system used in the 944 (1989–1991).

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Tools Required

• Phillips head screwdriver (#2)
• 10mm (3/8 inch) socket and ratchet
• Torque wrench (covering 5-10 Nm / 4-7 ft-lbs)
• Flathead screwdriver (small)
• Flashlight

Parts Required

• None (adjustment uses existing components, e.g., slip clutch assembly, 944 564 111 00)

Step-by-Step Procedure

Step 1: Prepare the Vehicle

1. Park the vehicle on a flat surface in a well-lit area.
2. Ensure the ignition is off and the sunroof is in the fully closed position.
3. Disconnect the negative battery terminal using a 10mm (3/8 inch) socket to prevent electrical issues.

Step 2: Access the Sunroof Motor

4. Open the rear hatch and locate the sunroof motor in the headliner, near the rear center of the roof.
5. Remove the headliner trim panel by gently prying it with a flathead screwdriver, exposing the motor assembly.
6. Remove the two Phillips screws securing the motor cover and set the cover aside.

Step 3: Adjust the Slip Clutch

7. Locate the slip clutch adjustment screw on the sunroof motor (a small slotted screw on the clutch assembly, 944 564 111 00).
8. Use a small flathead screwdriver to turn the adjustment screw clockwise until it stops, applying light pressure (do not overtighten).
9. Turn the screw counterclockwise exactly 1.5 turns to set the proper clutch torque, as specified for the late-model 944 sunroof.

Step 4: Reassemble the Components

10. Reinstall the motor cover and secure it with the two Phillips screws, tightening to 5 Nm (4 ft-lbs) using a torque wrench.
11. Snap the headliner trim panel back into place, ensuring it is flush with the surrounding trim.
12. Reconnect the negative battery terminal and tighten to 10 Nm (7 ft-lbs) using a 10mm (3/8 inch) socket.

Step 5: Test the Sunroof Operation

13. Turn on the ignition and operate the sunroof switch to open and close the sunroof fully.
14. Listen for smooth motor operation without grinding or slipping noises.
15. Verify the sunroof stops automatically when fully open or closed, indicating proper clutch adjustment.
16. If the sunroof slips or binds, repeat the adjustment (steps 7–9), turning the screw counterclockwise in 1/4-turn increments until smooth operation is achieved.
17. Drive the vehicle for 5 miles (8 km) to ensure consistent sunroof performance under vibration.

Post Procedure Checklist

• Confirm the sunroof opens and closes smoothly without slipping or binding.
• Check for no unusual noises (e.g., grinding, clicking) during sunroof operation.
• Ensure the headliner trim panel is securely reinstalled and flush.
• Verify all screws are tightened to specified torques (5 Nm / 4 ft-lbs for motor cover, 10 Nm / 7 ft-lbs for battery terminal).
• Check that the sunroof stops automatically at the fully open and closed positions.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• Youtube