When replacing the intermediate shaft (IMS) bearing in your Porsche Boxster, Cayman, or 911, the steps for pre-qualification and registration are essential yet often overlooked. Developed and refined by expert Porsche engine rebuilder, Jake Raby, of Flat 6 Innovations, these steps ensure that the IMS bearing replacement is performed on a healthy engine and that the work is documented for long-term reliability. Here’s an in-depth look at why these steps are crucial and how to complete them effectively.

Step 1: The Pre-Qualification Procedure – Ensuring Engine Readiness

Not every Porsche engine is a suitable candidate for IMS bearing replacement. The pre-qualification procedure, pioneered by Jake Raby and LN Engineering, helps determine if an engine is healthy enough for the IMS bearing replacement. Skipping this step could mean overlooking underlying engine issues that could compromise the new bearing or even lead to severe engine damage.

Here are the essential checks in the pre-qualification process:

• General Engine and Vehicle Health Check: Thoroughly inspect the engine and entire vehicle to identify any potential issues that could complicate the bearing replacement. Flat 6 Innovations emphasizes that IMS bearing replacements should not proceed on engines already showing signs of failure or neglect.

• Detection of Bearing Failure: Engines with IMS bearing failure are unsuitable for replacement, as debris from the failing bearing can spread throughout the engine, creating further issues. In cases of failure, the engine typically needs a complete teardown to address any residual damage.

• Cylinder Bore Scoping: Bore scoring, common in Porsche M96 and M97 engines, should be checked via scoping before the IMS bearing is replaced. Bore scoring could indicate deeper issues that require attention.

• Rear Main Seal Inspection: Some early 996 and Boxster engines suffer from chronic rear main seal leaks due to factory mis-machining. If there’s an existing leak with an updated PTFE Teflon seal in place, measuring the engine for mis-machining is critical before proceeding.

• Camshaft Timing Deviation: In early M96 engines (1997-2002 in Boxster and 1999-2001 in 996 models), wear on the chain ramps for the Variocam can occur at relatively low mileage (50-60k miles). If timing deviations exceed 4.5 degrees, replace the wear pads to prevent further issues.

Flat 6 Innovations has maintained a perfect track record with IMS replacements, thanks to this meticulous approach. Following these steps ensures that the replacement bearing is installed in an engine prepared to support it.

Step 2: Installation Registration – Documenting Your Investment

Once the IMS bearing has been replaced, the next essential step is registering the IMS bearing replacement. Whether you handle the installation yourself or have a professional do it, documenting the replacement properly is vital to maintaining warranty coverage and preserving the long-term health of your engine.

Here’s how to complete this process:

1. Apply the Serial Number Sticker: Inside the IMS Retrofit or IMS Solution kit, you’ll find a registration card and a serial number sticker. Place one of these stickers on the car as proof of the bearing’s installation.

2. Send Back the Original IMS Bearing: To complete your registration and warranty, send the original IMS bearing back to LN Engineering. They inspect and photograph the disassembled bearing to document its condition and check for debris that could indicate prior engine damage. If desired, you can request the bearing back as a keepsake (though disassembled), provided you cover the shipping cost.

3. Online Registration: Go to the IMS registration link provided on the registration card and upload your service invoice, proof of purchase, and any relevant photos from the installation. If a shop performed the replacement, include the shop’s invoice and details confirming that the pre-qualification steps were followed.

4. Final Submission and Record Keeping: Once you’ve completed the online portion, send the original bearing and registration card back. Be sure to include all the necessary information, such as your email address and the IMS serial number sticker, so the team can accurately match the bearing with your car’s records.

After LN Engineering receives your bearing, they inspect it for wear, debris, or any abnormalities. If the bearing meets all standards, they’ll complete the registration process and update their database within 60-90 days. Each bearing inspection and registration is documented with photos of the bearing and a record of its condition.

Why These Steps Matter

The IMS bearing replacement is a preventive, not corrective, measure. Skipping pre-qualification could mean missing critical engine issues that lead to costly repairs. Similarly, failing to register the installation could void the warranty on the replacement bearing, leaving the vehicle unprotected.

Together, the pre-qualification procedure and registration are what ensure the longevity of your investment in IMS bearing replacement. They provide a clear, traceable record of the replacement, backed by the peace of mind that comes with LN Engineering’s attention to detail and dedication to quality.