Clunking/rattling sound on hard acceleration

[Manuel]

I have a 99 XJ with 4WD(command trac) and 4.0L engine, auto trans.
When I accelerate hard from a stop, I get this clunking/rattling sound as I accelerate. It goes away after a second of acceleration. I thought maybe it had to do something with the front driveshaft or u-joints(just guesses).

I recently tried to do this same thing but with 4WD HI engaged. When I accelerated, the clunk/rattle upon acceleration was gone.

Any ideas as to what could be causing this?
Is it normal or not?

Thanks,
Manuel

[bgcntry72]

Is your rig lifted?
If so, how much?

[Bob 94 XJ]

If you are stock, you probably suffer from axle wrap. I also suffer from this, stock leaves just plain worn out..