Strut Removal and Replacement

Overview

This procedure outlines the steps to remove and replace the front strut assembly on a Porsche 944 with a 16v engine. The strut assembly, which includes the shock absorber and coil spring, is critical for the vehicle’s suspension, ensuring a smooth ride and proper handling. Replacing worn struts restores suspension performance and improves safety. This guide is tailored for DIY enthusiasts with mechanical experience, focusing on the 16v engine variant.

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Tools Required

• Metric socket set (includes sizes like 13mm, 17mm, 19mm)
• Metric wrench set (includes sizes like 13mm (1/2 inch), 17mm (11/16 inch), 19mm (3/4 inch))
• Scribe, paint pen, or brightly colored nail polish
• Air impact wrench
• Strut spring compressor (double or professional rigid type)
• Porsche tool 9186 or equivalent (for rebuilding old strut)
• Jack stands
• Floor jack
• Torque wrench (capable of 77 Nm (57 ft-lbs) and 150 Nm (111 ft-lbs))
• Vise (for rebuilding old strut)

Parts Required

• Strut insert (if replacing), 944 343 031 00 (944-specific)
• Strut bearing (if needed), 944 343 027 01
• Automatic transmission fluid (ATF) or thin oil (optional, for strut housing cooling)

Step-by-Step Procedure

Step 1: Prepare the Vehicle

1. Disconnect the negative battery cable to prevent electrical issues during the procedure.
2. In the engine compartment, locate the four strut mounting bolts on top of the strut tower. Loosen each bolt several turns using a 13mm (1/2 inch) socket, but do not remove them yet.
3. Raise the vehicle using a floor jack and secure it on jack stands. Ensure the vehicle is stable before proceeding.
4. Remove the front wheels using a 19mm (3/4 inch) socket to access the strut assembly.

Step 2: Remove the Strut Assembly

5. Locate the brake line clipped to the front strut. Gently remove the brake line from the clip to free it from the strut.
6. At the bottom of the strut, identify the two bolts attaching the strut to the spindle assembly. The top bolt is an eccentric bolt used for camber adjustment. Mark its orientation on the strut using a scribe, paint pen, or brightly colored nail polish to ensure proper alignment during reinstallation.
7. Remove the eccentric bolt and the bottom retaining bolt using a 19mm (3/4 inch) socket and wrench. Pull the strut away from the spindle until it is free from the bottom of the assembly.
8. Support the strut to prevent it from falling. Remove the four mounting bolts at the top of the strut tower using a 13mm (1/2 inch) socket. Carefully lower and remove the strut from the vehicle.
9. If replacing the strut, note the eccentric bolt alignment mark from Step 6 and transfer it to the new strut to maintain camber settings.

Step 3: Replace the Strut Insert (If Rebuilding)

Caution: Use extreme care when compressing the coil spring. Double spring compressors (common in auto parts stores) can be dangerous if the spring slips. Make small adjustments, alternating sides, to keep the spring secure. For safety, consider using a professional rigid spring compressor or have a suspension shop perform this step.

10. Using a strut spring compressor, compress the coil spring until there is only slight pressure on the strut assembly’s top plate.
11. Using an air impact wrench and a 19mm (3/4 inch) socket, remove the spring strut bearing retaining nut. The impact wrench prevents the strut rod from spinning.
12. Remove the bearing from the strut and slide the strut assembly out of the spring.
13. If rebuilding the old strut, clamp the assembly in a vise. Use Porsche tool 9186 or an equivalent to remove the strut insert cap.
14. Remove the old insert from the strut housing. Clean the inside of the housing and remove any residual oil.
15. Install the new strut insert, 944 343 031 00. Ensure the spacer is installed between the cap and the cartridge.
16. Torque the cartridge cap to 150 Nm (111 ft-lbs) using a torque wrench.

Note: To improve cooling, you may fill the shock absorber housing with thin oil or ATF, but do not exceed 2/3 full if the cartridge touches the bottom of the housing. Excess oil may leak when hot, leading to incorrect diagnosis of a defective strut.

Step 4: Reassemble the Strut

17. Place the coil spring onto the new or rebuilt strut assembly.
18. Install the strut bearing, 944 343 027 01, onto the strut assembly.
19. Using an air impact wrench and a 19mm (3/4 inch) socket, tighten the spring strut bearing retaining nut to 77 Nm (57 ft-lbs).

Step 5: Install the Strut Assembly

20. Insert the new or rebuilt strut assembly through the opening at the top of the strut tower. Loosely install the four retaining nuts on top of the strut tower using a 13mm (1/2 inch) socket.
21. Slide the bottom of the strut onto the spindle. Install the bottom retaining bolt and the top eccentric bolt, aligning the eccentric bolt with the mark made during removal.
22. Tighten the eccentric bolt locking nut and the bottom retaining bolt locking nut to 85 Nm (63 ft-lbs) using a torque wrench.
23. Tighten the four retaining bolts on top of the strut tower to 25 Nm (18 ft-lbs).
24. Reattach the brake line to the clip on the strut.
25. Install the front wheels using a 19mm (3/4 inch) socket and lower the vehicle from the jack stands.

Post Procedure Checklist

• Verify that all bolts are torqued to the specified values (top strut tower bolts: 25 Nm (18 ft-lbs), bottom strut bolts: 85 Nm (63 ft-lbs), strut bearing nut: 77 Nm (57 ft-lbs), cartridge cap: 150 Nm (111 ft-lbs)).
• Ensure the brake line is securely clipped to the strut and not pinched or damaged.
• Check that the eccentric bolt is aligned with the mark to maintain proper camber.
• Take the vehicle to an alignment shop to verify camber settings as soon as possible.
• Test drive the vehicle for 5 miles (8 km) to check for abnormal noises or handling issues.

Sources

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