Loren - Intermediate shaft bearing

[pjslowik]

Loren, Is number 13, "Housing" the part that contains the bearing that commonly fails? If not, where is it? If so, can this be removed and replaced without dismantling the engine? Has anyone you know of ever done a replacement in anticipation of a failure? Thanks.

Intermediate_shaft.pdf

[Loren]

The most common failure on the intermediate shaft ( to my knowledge) is the seal. All that needs to happen is for one of the cam chains to jump a tooth and your engine is toast (valves collide with pistons or the chain breaks and thrashes the case).

The intermediate shaft drives all four cams and the engine pretty much needs a full disassembly to change it (retime the cams etc.).

Porsche needs to analyze and fix whatever causes these failures. Next time I (or Tool Pants) see Peter Smith we'll ask him what the factory says about the IMS failures.

[Tool Pants]

What I was told by Peter a long time ago is that the early cars had a double bearing. The early cars were 2.5 liter. Then Porsche went to a single bearing. I forget when. When I started Boxstiring in 1999 I do not remember people on the message boards talking about intermediate shaft failures because back then there was only the 2.5. Now when I see a report of an intermediate shaft failure it is the newer cars. Don't quote me, but I seem to remember Porsche went with a larger bearing for the 987.

Pic of the shaft from a UK board.

[pjslowik]

Thanks both for replying. Nice pic of shaft. Looks like he threw a rod on that one.

A factory rep did tell me, on my last engine replacement, that they went from a double bearing to a single, and now back to a double. He said I had the updated bearing (double), thrust washer, and RMS, and that now I should have a good engine. That was in June. I have been racking up the miles this summer, trying to "prove" the engine before the warranty runs out next July.

Anyway, I can't seem to find the bearing in any of the drawings.