Help..Noise from drivetrain

[Joshua]

Suicide prevention wanted...1998 TJ sport

So this sounds starts coming from somewhere under the jeep, a whirling/grinding. I hear it on throttle and coasting but louder on coasting. Starts around 20mph and gets louder from there.
Ok so far I have:
Replaced both front wheel bearing/hubs
Replaced both rear wheel bearings
Replaced both ujoints on rear driveshaft
Then I had the transmission rebuilt(I thought it was coming from the output shaft bearing)!!! Yeah wrong 1,000$
but I got a new clutch out of it...still not happy though

I have driven up and down the street with friends hanging out listening for where its coming from and everyone points to something different.

I am completely out of ideas, I have tried every trick I know in trying to isolate where the crap this noise is coming from. Thanks for any help in advance.

[Grovehunter]

I just had a nightmare similar to yours three weeks ago. I knew right away from experience that I had wiped out a ring and pinion. Actually, the ring gear was ok, But the pinion wasn't. Too much slop under load going down hill was the culprit. I still managed to get home from near Tahoe to So Cal. thru the mountains of Yosemite and Sequoia, 600 miles of stress...
The dealer wanted $2500.00 to rape me. I went to the junkyard and bagged another drum to drum set up for 4 bills and did it myself in four hours. The ring gear and pinion on the new one still had the machine marks on them!!
Hope this helps you?
GH
BTW/ I can't say enough about synthetic fluids!