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MNBoxster · 01-10-2006, 05:53 AM

Hi,

A couple of points:

The Flywheel used in the Boxster is a Dual Mass Flywheel and Porsche does not recommend that it be machined or refaced, rather, that it be replaced. Add to this that the Flywheel on the M96 Engine contains the Vibration Damping usually done by the Pressure Plate (no springs on the M96 Pressure Plate - they're on the Flywheel instead). Machining or Refacing will seriously weaken it and it could shatter at high RPM, creating all sorts of issues.

Also, during initial Factory assembly, the Rear Main Seal (RMS) is seated to a depth of 11mm. When replacing the RMS, the new seal should be seated to a greater depth of 13mm so that the sealing lip is seated on a clean part of the Crankshaft because the previous seal will have left a wear mark on the Crank making it difficult for the new Seal to properly seal.

Your RMS makes contact with the spinning Crankshaft and as such is a Sacrificial Seal - EVERY RMS will eventually wear out and will leak. Unless your leak was caused by an Out-of-Round Crank or Out-of-Tolerance Center Bore in the Block, which will greatly accelerate it's Wear Rate, you can replace it fully confident that it will last for it's designed lifespan.

If yours is currently leaking, you are on borrowed time. Some leaky seals will go many XXXXmi. before they become catastrophic, others will not - no way to tell which will and which will not. If you let it get to this stage, SERIOUS Engine and Clutch damage Can occur in just a few minutes running time - remember, it's the RMS which contains the Oil in the Motor! I don't want to scare you, just give you a clearer picture.

If it were me, I'd consider having it done at the nearest opportunity combined with other work such as a clutch to better ammortize the Labor Costs. Also, do some research, many Dealers and Owners have had good luck replacing the Stock Boxster Part with the RMS from the Cayenne which apprently has more give to it and so better seals those engines which are Out-of-Tolerance. Hope this helps...

Happy Motoring!... Jim'99

01-10-2006, 05:53 AM	#3
MNBoxster Registered User Join Date: Sep 2005 Location: Minneapolis/St. Paul, Minnesota, USA Posts: 3,308	Hi, A couple of points: The Flywheel used in the Boxster is a Dual Mass Flywheel and Porsche does not recommend that it be machined or refaced, rather, that it be replaced. Add to this that the Flywheel on the M96 Engine contains the Vibration Damping usually done by the Pressure Plate (no springs on the M96 Pressure Plate - they're on the Flywheel instead). Machining or Refacing will seriously weaken it and it could shatter at high RPM, creating all sorts of issues. Also, during initial Factory assembly, the Rear Main Seal (RMS) is seated to a depth of 11mm. When replacing the RMS, the new seal should be seated to a greater depth of 13mm so that the sealing lip is seated on a clean part of the Crankshaft because the previous seal will have left a wear mark on the Crank making it difficult for the new Seal to properly seal. Your RMS makes contact with the spinning Crankshaft and as such is a Sacrificial Seal - EVERY RMS will eventually wear out and will leak. Unless your leak was caused by an Out-of-Round Crank or Out-of-Tolerance Center Bore in the Block, which will greatly accelerate it's Wear Rate, you can replace it fully confident that it will last for it's designed lifespan. If yours is currently leaking, you are on borrowed time. Some leaky seals will go many XXXXmi. before they become catastrophic, others will not - no way to tell which will and which will not. If you let it get to this stage, SERIOUS Engine and Clutch damage Can occur in just a few minutes running time - remember, it's the RMS which contains the Oil in the Motor! I don't want to scare you, just give you a clearer picture. If it were me, I'd consider having it done at the nearest opportunity combined with other work such as a clutch to better ammortize the Labor Costs. Also, do some research, many Dealers and Owners have had good luck replacing the Stock Boxster Part with the RMS from the Cayenne which apprently has more give to it and so better seals those engines which are Out-of-Tolerance. Hope this helps... Happy Motoring!... Jim'99 Last edited by MNBoxster; 01-10-2006 at 09:09 AM.