Well I know it was bound to happen sooner or later, but today on my way to work my cardan shaft has appeared to fail on me. My 2004 CS has just about 91k miles on it, and as I was accelerating up hill I could hear the drive shaft under me start rattling like crazy. I have decided to go with the rebuilt and upgraded drive shaft from vertexauto. I just think it would be a waste to go with an oem one that is twice the cost. My question though is that is it necessary to also replace the flex disc at the same time? And if I do , is there any other parts necessary other than the upgraded flex disc? Thanks in advance for any help

 

With almost 100k miles on it - it probably would be smart to replace the flex disk (called a "Guibo" in the BMW world..) It might last another 91k miles, or it might decide to crap the bed 10 miles after the shaft is replaced. Are you willing to bet the labor cost to replace it later that it's going to last?

To me - it's one of those "do it while in the area.."

Also - dunno if this is true on a Cayenne, but on other cars I've owned the bolts holding the flex-disk and rear connection to the differential in place were one-time use, since they had factory applied Loctite(tm) on them. I'd suggest at a minimum making sure if the bolts are reused that you apply medium strength (blue) Loctite to them. And AFAIK - the disk hasn't been "upgraded" - it's a pretty standard design that German cars have been using for decades..