[turbo23dog]

I was at a local independent shop specializing in Pcars this past Thursday to pick up some tune up parts. It seems they just replaced a 3.4L engine from a 2002 996 due to IMS failure and the old engine was in a corner of the shop sitting on the pallet the new engine had arrived on.

The tech showed me the actual broken end of the Intermediate Main Shaft. I was able to hold the broken end of the shaft in my hand and it still had the "nut" on the end of it. To my untrained eye, it looked like the nut was over tightened and the stress over time caused the metal to fatigue and the shaft seperated at its weakest point. The tech didn't think so. He did think that the failure patten was random and offered that maybe random batches of the shafts were defective from the factory that supplies the shafts (something gone wrong with the forging process), meaning that its a total crapshoot to which IMS your engine got at the time it was assembled.

Again, no science behind this, just pure speculation, but interesting nontheless.