Not another IMSB thread...but...

[M711]

I was just curious.

In the

Pelican Technical Article:
Intermediate Shaft Bearing
Replacement and Upgrade (IMS)

I see this list of serial numbers/bearing types.

Engine Number Model Bearing Type
Up to engine # M 651 12851 Boxster 2.7L M96.22 Double Row Bearing
Up to engine # M 671 11237 Boxster S 3.2L M96.21 Double Row Bearing
Up to engine # M 661 14164 Carrera 996 3.4L Double Row Bearing
From engine # M 651 12852 Boxster 2.7L M96.22 Single Row Bearing
From engine # M 651 11238 Boxster S 3.2L M96.21 Single Row Bearing
From engine # M 661 14165 Carrera 996 3.4L Single Row Bearing
All 2005 Boxster 987 (maybe some 2006 models) Single Row Bearing
All 2005 Carrera 997 (maybe some 2006 models) Single Row Bearing
Maybe some 2006 Cayman models Single Row Bearing

Well, my 02 Boxster has this engine serial number:

M96/226520xxxx. This serial number is stamped at the proper place on the car's original engine and I bought the car new back in '02.

I do not see any "652" numbers in the list above and I wondered what kind of bearing my car's engine might have?

[JFP in PA]

Do not place a lot of faith in list that claim they can tell you what style IMS bearing is in which engine, they have very often been proven wrong.

An '02 engine should be a single row.

[M711]

The car was built in 10/2001.

[dmcummins]

So my 2000s may have a double row bearing. Is this better?

[JFP in PA]

Originally Posted by dmcummins

So my 2000s may have a double row bearing. Is this better?

You have to remember that 2000-2001 was a transitional period for Porsche, which simply translates into the fact that any engine could have either a dual or a single row bearing. There is no known or accepted list of serial numbers or any other magical way to discern which bearing is in the engine, you have to pull the flywheel off and look at the IMS flange to find out which style it is. Up to 2000, the engines were all dual row, from 2002 to 2004, they were all single row, and then in 2005 Porsche entered another transitional period where the engine could be either a serviceable single row or the impossible to change without taking the engine apart "final solution" IMS that was used until the 9A1 engine was introduced. Again, this requires pulling the flywheel to find out what is in there.

The OEM dual row bearing was the most durable of the factory designs, but they still failed, just in smaller numbers. So your take away for all this should be that all factory IMS bearings can and do fail, but not at the same rates.

[M711]

Based on a pic I have of my car's IMS end plate when it was exposed for an RMS/IMS end plate R&R it looks like my car's engine has the shallow end plate and thus a dual row bearing.