Crankshaft – Front Oil Seal Replacement

Overview

This procedure replaces the front crankshaft oil seal on your Porsche 944 S2 (3.0L engine), which prevents oil leaks from the crankshaft at the front of the engine. Keeping this seal in good condition is crucial to maintain proper oil pressure and avoid engine damage.

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Tools Required

• Metric wrench set (sizes including 10mm (3/8 inch), 13mm, etc.)
• Metric socket set (sizes including 13mm, 17mm, etc.)
• Jack stands or ramps
• Floor jack
• Porsche Timing Belt Tension Tool (P9201)
• Flywheel Lock (P9206)
• Balance Shaft Pin Spanner (P9200) or equivalent
• Gear puller
• Seal puller

Parts Required

• Crankshaft oil seal – 999 113 331 50 (38 x 52 x 7 mm, specific to 944 S2 from 1989-1991)
• O-ring – 999 707 283 40

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Balance Shaft Belt Removal
• Flywheel Lock Installation
• Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1
• Air Filter Housing and Air Flow Sensor – Removal
• Distributor Cap and Rotor Replacement
• Camshaft and Balance Shaft Belt Installation
• Balance Shaft Sprocket Installation and Alignment Check
• Balance Shaft Belt Tension – Checking and Adjusting

Step-by-Step Procedure

1. Prepare the Vehicle

1. Disconnect the negative lead from the battery to ensure safety while working on the engine.
2. Raise the front of your Porsche 944 S2 using a floor jack, then secure it on jack stands or ramps. Ensure the vehicle is stable and at least 1 foot (0.3 meters) off the ground for easy access.

2. Remove the Timing and Balance Shaft Belts

3. Follow this link to ensure this step – Balance Shaft Belt Removal – of the process is followed accurately. This will expose the front crankshaft area on your 3.0L engine.

3. Disassemble the Front Components

4. Remove the rear timing cover by loosening its bolts with a 13mm wrench and carefully lifting it off.
5. Take off the oil pump thrust washer, O-ring (999 707 283 40), and drive sleeve from the crankshaft. Use a gear puller if the drive sleeve is stuck.

4. Inspect and Replace the Drive Gear if Needed

6. Check the oil pump drive gear (drive sleeve) for wear. Look closely for a ridge or scoring that could prevent the new seal from working properly. If you see damage, replace it with a new drive sleeve suited for the 944 S2 (refer to a separate guide for part numbers specific to the 3.0L engine).

5. Remove and Replace the Crankshaft Oil Seal

7. Use a seal puller to carefully remove the old crankshaft oil seal from the oil pump housing. Avoid scratching the housing surface.
8. Install the new crankshaft oil seal (999 113 331 50) into the oil pump housing. Press it in evenly by hand or with a seal installer tool until it sits flush.

6. Reassemble the Front Components

9. Slide the oil pump drive sleeve back onto the crankshaft, ensuring it seats properly.
10. Install a new O-ring (999 707 283 40) and the oil pump thrust washer onto the crankshaft.
11. Reattach the rear timing cover and tighten its bolts to 20 Nm (15 ft-lbs) using a torque wrench.

7. Reinstall the Timing and Balance Shaft Belts

12. Follow this link to ensure this step – Balance Shaft Belt Installation – of the process is followed accurately. This ensures proper timing on your 3.0L engine.

8. Finalize the Procedure

13. Lower the vehicle carefully off the jack stands or ramps using the floor jack.
14. Reconnect the negative battery lead to restore power.

Post Procedure Checklist

• Start the engine and let it idle for 5 minutes, checking for oil leaks around the front crankshaft area.
• Inspect the timing belt tension after driving 5 miles (8 km) to ensure it’s still within spec (use the Porsche Timing Belt Tension Tool P9201).
• Confirm no unusual noises come from the engine, indicating proper seal and component installation.

Sources

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