Knocking/rattling sound under console on start

I searched, but couldn't find any threads related to this problem/annoyance. Whenever I start the jeep, I always hear a rattle/knock that seems to come from right under the console (shifter area). Is this normal, or is it maybe a sign of something bad that will come to pass? It's a 99 if that matters.

I've got the same thing going on. It also happened on my old TJ.

On my TJ it was the t-case bushing. Quick $40 fix at a mom & pop garage.

I'd bet it's the same thing.

I'm dropping mine off at the dealer on Wednesday to have them fix it for me since I also want them to fix my 4wd indicator on the dash.

I'll let you know if the bushing kit was the problem.

DD

Could be the trans mount too...

Thanks for the quick replies! So could I crawl under it and shake the Tcase to check this out, or would it not be enough force to duplicate it by hand? Also, about the "quick" fix at a mom & pop...would that be something that the average guy could fix or is it a big job without a garage/right tools? I like to ry to fix anything I can myself, but I don't pretend to be a gear head or anything....just your average wrench guy.

EDIT:

I did some research on the transfer case bushing thing... I don't think that that is the problem because it's only on startup and doesn't seem to be originating in the 4x4 shifter. The knocking is pretty loud sounding too....I'm thinking the transmission mount as SPVFD47 suggested. Anyone else?

Let it cool and then crawl under and hit the Cat converter with your fist.Bet it makes the same sound you hear at start-up.
If you have less than 80 K on the Jeep take it back for a replacement on them,if over 80K then it,s out of your pocket.
Wayne