Our C4 chassis UrS4s and S6s use a two-piece driveshaft (aka "propeller shaft") that has a CV joint at the front, a Hotchkiss U-joint in the middle and a CV joint at the end. There is also a steady bearing in the middle. None of these parts are available seperately. The dealer will only sell you a complete unit, Item 1, in the diagram below:
Here is what the centre bearing looks like:
![](http://www.034motorsport.com/oscthumbwm/w/550/h/567/q/95/f/jpg/fltr/wmi%7CphpThumb/watermarks/034watermark%7CC%7C20%7C0/hash/3be509a594ddcd3b48732571c2d61ba9/src/images/URS4_DS_SUPPORT.jpg)
Photo courtesy of 034 Motorsports (see link below)
Being the sly and clever owners we are, alternative "solutions" have evolved to solve problems with the CV joints and/or center bearing. Here are some of them:
Tornado//S6's Driveshaft R&R post
Blaufergnuegen's Drive Shaft Kit
034's centre bearing replacement
Link to quattro20v's Driveshaft rebuilt post