Porsche 996 Rear Main Seal Part Number: Complete Guide

The rear main seal (RMS) on a Porsche 996 is a well-known weak point. Oil leaks from this seal can lead to messy driveways and, if ignored, potential clutch damage. If you’re searching for the correct part number, you likely need to replace yours or are planning ahead. This guide covers the exact Porsche 996 rear main seal part numbers, the differences between OEM and aftermarket options, and practical advice for a successful repair.

Understanding the Rear Main Seal Issue

The rear main seal sits between the engine’s crankshaft and the bell housing. Over time, the seal’s rubber hardens and cracks, causing oil to seep past. On the Porsche 996, this is especially common on models from 1998 to 2001 (M96 engine). Early 996s have a single-piece seal; later cars use an updated design. Using the wrong part number can result in leaks or seal failure soon after installation.

Porsche 996 Rear Main Seal Part Numbers

OEM Part Numbers

Porsche has revised the rear main seal several times. The current OEM part number for most 996 models (including Carrera, Carrera 4, and Turbo) is 996-113-212-06. This supersedes earlier numbers like 996-113-212-03, 996-113-212-04, and 996-113-212-05. The -06 version includes an improved lip design and a metal outer casing for better fitment.

For 996 Turbo and GT3 models with the Mezger engine (2001-2005), the part number is different: 996-113-213-03. This seal is larger to accommodate the different crankshaft flange.

Check your engine code or VIN to confirm which seal you need. The M96 engine uses the -06 seal; the Mezger engine uses the -03 seal.

Aftermarket Options

Several reputable brands offer RMS replacements: Corteco, Victor Reinz, Elring, and INA. These are often OES (Original Equipment Supplier) manufacturers—Corteco supplies many original Porsche seals. Their part numbers cross-reference:

• Corteco: 42013378B (fits M96)
• Victor Reinz: 70-32310-20
• Elring: 128.090 (also sold as 128090)

Aftermarket seals can be cheaper, but quality varies. Stick with known brands. Avoid no-name seals from discount sellers—they may have improper rubber compounds or inaccurate dimensions.

How to Choose the Right Seal

OEM vs Aftermarket

OEM (Porsche-branded) seals cost about $40–$60 at dealerships. Aftermarket brands like Corteco run $20–$35. For a part this critical, spending the extra $20 for an OEM seal is common advice among Porsche specialists. However, if you’re on a tight budget, a Corteco seal is essentially the same as OEM because Corteco makes the original part. Check the box: some aftermarket seals are identical except for branding.

Common Mistakes

• Using the wrong part number: The M96 and Mezger seals are not interchangeable. Installing an M96 seal on a Turbo engine will leak immediately.
• Not replacing the guide tube O-rings: When doing the RMS, replace the oil separator and guide tube O-rings (part 996-107-233-00). These often leak separately.
• Skipping the sealant: The RMS should be installed dry? No—Porsche recommends a thin layer of anaerobic sealant on the outer metal surface to prevent corrosion and ensure a tight fit. Use Loctite 574 or equivalent.
• Improper installation depth: The seal must be flush with the crankcase surface, not recessed or protruding. Use a seal driver tool.

Step-by-Step Installation Overview

Replacing the RMS is an intermediate-level job. It requires removing the transmission and clutch. Here’s a high-level sequence (always consult a service manual):

1. Disconnect battery and drain engine oil.
2. Remove exhaust, driveshaft, and transmission (support engine with a hoist).
3. Remove the pressure plate, clutch disc, and flywheel (or flexplate on Tiptronic).
4. Pry out the old rear main seal using a small pick or seal puller. Be careful not to damage the crankshaft surface.
5. Clean the sealing surface with brake cleaner. Check for burrs or scratches.
6. Apply anaerobic sealant to the outer rim of the new seal (if specified).
7. Drive the new seal in using a seal driver until flush. Do not overdrive or tilt.
8. Reassemble clutch and transmission in reverse order. Torque flywheel bolts to spec.
9. Refill oil and check for leaks before driving.

If you’re not comfortable with mechanical work, budget $800–$1,200 for a shop to do it, as it’s labor-intensive.

Practical Tips for a Lasting Repair

• Replace the clutch while you’re in there: Since the transmission is already out, consider a new clutch kit if yours is worn. Saves labor later.
• Use factory sealant: Permatex Anaerobic Gasket Maker (51813) works well if you can’t find Loctite 574.
• Inspect the crankshaft flange: If there’s a groove from the old seal, you may need a speedi-sleeve (National 99182 or similar) to salvage the surface.
• Break in the seal: After repair, avoid high RPM for the first 500 miles to let the seal lip seat properly.

Final Recommendation

For most Porsche 996 owners, the best choice is the OEM part number 996-113-212-06 (M96 engine) or 996-113-213-03 (Mezger engine). Buy from a Porsche dealer or trusted online shop that sells genuine OEM parts. If you want to save a few dollars, Corteco is a reliable aftermarket alternative. Never install a used seal. And always replace the guide tube O-rings at the same time—it’s cheap insurance against another leak.

Knowing the correct part number is the first step. Taking the time to do the job right—or paying a pro to do it—will keep your 996 leak-free for years.