[V8] Center Driveshaft bearing and clunking

[Mark Kalbskopf]

This is only generically V8 related but . . .
Does anyone have experience of how much play is acceptable in a center  
drive shaft support bearing?
I'm talking about pushing the driveshaft up and down so the rubber  
compresses in the bracket.
My daughter's A4 Quattro (manual) has a  clunk or thump going on on  
every time you let off or go back on the acceleration.
I crawled underneath and expected to see the rubber surrounding the  
drive bearing all shot but it wasn't. Now, the rubber had some small  
cracks in it when flexed but it was all solid.
The shaft had about 3/4 to 1 inch of flex  between me pulling it down  
and pushing it up.
The U-joint had no play, neither did the CV joints and I couldn't see  
any obvious problem with the transmission mounts.
Is 3/4" too much flex? How solid is a new one?

Mark