Front driveshaft inner joint repl.
 

Well it looks like my right front driveshaft inner joint has a large amount of play, so it will need replacing. Unbelievably the outer is fine, but may replace that one while I'm in there. The dealership is saying 7 hrs to do the job, my local shop looked it up on Mitchell and it states 2hrs. I'm going to replace all the brake pads and rotors this weekend so I'm figuring I'll be about halfway into the job... Any wisdom on how long this should take? Also is the GKN 95534990201 replacement joint @ $250 or so the best way to go for this repair? Any experience with the A-1 Cardone replacements? Both joints replaced for $100 seems too good to be true!
Hopefully this will fix my huge vibration issue under acceleration in the 2004 Cayenne TT...

After closer inspection, it looks like the joint itself is not bad, but the axle has a little play in the housing. I don't know if this is a common problem, but in looking at it I can understand the dealership making the diagnosis they did, but a new inner CV joint will not rectify this symptom. However I need to get rid of this bad vibration problem, and cannot determine if that problem (how to fix?) will fix the vibration or if it means a new tranny.

The likely problem is the main driveshaft bearing carrier. The driveshaft to the rear has a CV so that the shaft doesn't make a straight shot back to the rear diff. And to keep that 'bend' in the right place, there is a driveshaft carrier. --a bearing (on the shaft) surrounded by a rubber damper (doughnut) surrounded by a metal frame. What happens is, the rubber rips and the bearing starts to wobble in the metal carrier.

You can get much info on this problem in my thread http://forums.pelicanparts.com/porsche-cayenne/645350-drive-shaft-bearing-issue-dont-buy.html ...it has some good links by others.

:)island is right, driveshafts go out much more often than axles