[Oldcarguy]

Originally Posted by thstone

. . . The air cooled IMS used a regular (plain) bearing that was continuously fed pressurized engine oil for lubrication (and as such, they never failed). A bad bearing resulted in a knocking sound like a bad rod due the increased clearance, but they never resulted in catastrophic engine failure.

Porsche followed this tried and true approach (oil fed plain bearing) on the other end of the M96 intermediate shaft where the oil pump is located and this is why that end of the shaft never fails - failure is always at the ball bearing side. Porsche should have figured out a way to get oil to both ends of the IMS. . .

Blah, blah, blah in the article. Nothing we didn't already know. Turns out I really love my new-to-me 2004 550 anniversary S. Almost as responsive as my Tonykart (well, not quite). I'll be upgrading from my current LNE IMSB to the 'Solution' prior to the LNE recommended interval for IMSB replacement or when oil filter exams dictate. #317 is in excellent condition and the 'Solution' should insure that it will be one of the long term survivors (if I don't wrap it around a tree or have a close encounter of the deer kind)

PS: the comments at the end of the article once again serve to remind us that the M96 is not the only engine with design problems. And remember, it's better to be infamous than unknown.