Crankshaft – Rear Oil Seal Replacement – 2.5L NA

Overview

This procedure replaces the rear crankshaft oil seal on all Porsche 944variants (8-valve engine) to prevent oil leaks from the rear of the engine, which can damage the clutch or cause oil loss. The process involves removing the clutch and flywheel to access the seal. This guide applies to both pre-1985.5 (1982–1984) and 1985.5 onwards (1984–1988) models.

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Tools Required

• Metric wrench set (8mm to 19mm, 5/16 inch to 3/4 inch)
• Metric socket set (8mm to 19mm, 5/16 inch to 3/4 inch)
• Torque wrench (10–150 Nm, 7–110 ft-lbs)
• Jack stands or ramps
• Floor jack
• Flywheel lock (P9206)
• Seal puller
• Seal installer

Parts Required

• Rear crankshaft oil seal: 999 113 426 41
• Flywheel bolts (optional, replace if worn): 944 102 205 02 (8 required)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Clutch Removal
• Flywheel Removal
• Flywheel Installation

Step-by-Step Procedure

Step 1: Prepare the Vehicle

1. Disconnect the negative battery lead to ensure safety during the procedure.
2. Raise the vehicle using a floor jack and secure it on jack stands or ramps for access to the transmission and engine rear.

Step 2: Remove the Clutch

3. Follow this link to ensure this step – Clutch Removal – is followed accurately to remove the clutch assembly and expose the flywheel.

Step 3: Remove the Flywheel

4. Follow this link to ensure this step – Flywheel Removal – is followed accurately to remove the flywheel. Use a flywheel lock (P9206) to prevent crankshaft rotation.
5. Inspect the flywheel for wear or damage. If replacement is needed, refer to the Porsche 944 Workshop Manual for part numbers.

Step 4: Remove the Old Rear Crankshaft Oil Seal

6. Use a seal puller to carefully remove the old rear crankshaft oil seal from the engine block housing. Avoid scratching the housing or crankshaft surface.
7. Clean the seal seating area in the engine block with a lint-free cloth to ensure a smooth surface for the new seal.

Step 5: Install the New Rear Crankshaft Oil Seal

8. Press the new rear crankshaft oil seal (999 113 426 41) into the engine block housing using a seal installer or a socket of similar diameter. Ensure the seal is seated evenly and flush with the housing.

Step 6: Reinstall the Flywheel

9. Follow this link to ensure this step – Flywheel Installation – is followed accurately to reinstall the flywheel.
10. Install new flywheel bolts (944 102 205 02) if the old bolts show signs of wear or stretching. Tighten the bolts to 90 Nm (66 ft-lbs) using a torque wrench in a star pattern.

Step 7: Reinstall the Clutch

11. Follow this link to ensure this step – Clutch Installation – is followed accurately to reinstall the clutch assembly.

Step 8: Finalize the Procedure

12. Lower the vehicle from the jack stands or ramps using a floor jack.
13. Reconnect the negative battery lead.

Post Procedure Checklist

• Verify that the flywheel bolts are torqued to 90 Nm (66 ft-lbs).
• Check that all tools and debris are removed from the engine and transmission area.
• Inspect the new seal for proper seating and alignment with the engine block housing.
• Start the engine and check for oil leaks around the rear crankshaft seal area.
• Test the clutch operation by engaging gears while stationary.
• Drive the vehicle for 5 miles (8 km) and recheck for leaks, abnormal noises, or clutch issues.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manuals
• YouTube