Originally Posted by FredR

Malcolm,

Does the S4 have the 28mm shaft [tapered] or the 25mm earlier design?

Rgds

Fred

Originally Posted by Constantine

I used the word "pinned" to describe how the manual transmission drive shafts of the 924/944/968 and 928 are held in place at the back of the crankshaft. What you describe is correct, the drive shaft, or the short shaft, depending on which model Porsche you are referring too, has an end nub which is inserted into a bearing which is inserted into the end of the crankshaft, thereby restricting its movement or "pinning" it down. This system differs in the 928 automatic drive shaft configuration where the end of the drive shaft is held by the front flex plate clamp. If you don't restrict the movement of the drive shaft end somehow, the drive line harmonics will vibrate the unsupported drive shaft end.

I used "pinned" as in the definition found on the website www.thefreedictionary.com "to hold fast, immobilize," not in the literal sense of where a thin metal rod pierces through an object holding it in place. Sorry for any confusion.