2001 LS V8 with 86000 miles has a knocking noisethat seems to come from under the body when costing. The noise does not occure under acceleration and would go away when braking. Any ideas? I do have access to AllData info which indicates that the center bearing can be changed without to much problem.

whet centre baring ar you talkinge abot?

That's what I'm wondering too. Are you talking about the joint that links the 2 piece driveshaft? Of course that's not a bearing, but if it's directly under the car... I'm just guessing.

whet centre baring ar you talkinge abot?

Lol thats what I was thinking

I have the same problem that I am trying to figure out. My knocking sound like a heavy object rolling around under the console. I only hear it when I am taking off and lasts about 2 seconds. (as if an object was in the trunk rolling around) I don't hear it in reverse. There are no vibrations up to 120mph anyways. It is really bad if I step on it from a dead stop or rolling 1-3mph. I have to replace the transmission control pack this week but I don't think it has anything to do with that. I got a check transmission light about 2 weeks ago and this problem rose about a week ago. If I take off very very slow I don't hear it. Its also no louder with the windows open.

I had the same problem, it is related to a front brake caliper and or the clips that are part of the assembley. They are worn out, fairly simple replacement.
The sound doe's go away while braking.