I have a 2002 x type 3.0 auto. Its been having a vibration issue for a while now and i have a few thoughts about it. First off. accelerating going between 30 and 40 in third gear their seems to be a vibration coming from the center of the car gets worse if you try to pick up speed faster while vibrating but doesnt vibrate much if taking it easy. I think its the drive shaft center support. Is that the same as the centering bearing?

 

sounds like a loose or really bad center support bearing. This bearing goes by many names.

center support bearing
driveshaft support bearing
propshaft bearing

and basically any combination of those words. As for changing the bearing, it is pretty simple. google "center support bearing jaguar x type" and buy one for around $150. Take off your driveshaft and take out the two bolts holding the bearing to the chassis. Take the old driveshaft with old bearing and new bearing to a shop and have them press the old one off and the new one on. Don't pay a dealer to screw you for $2k or more on this.