i have a 05 4x4 2500 four door cummins and recently noticed when turning sharply at low speed it makes a clunking noise either direction you turn, i crawled underneath and everything feels tight the outer u joints seemed tigh also noticed seapage from the steering box is this common problem,

 

I bet its the u-joints on the front axle. These are notorious for going out. I just replaced mine a few months ago.

 

I just took my truck in and they replaced all of the kingpin bearings and both ujoint's in the front along with the short side stub axle (it only cost me $100.00 deductible). It could also be the drag link from the steering box to the tie rod AND the tie rod too. I am in process of building a prototype drag link and tie rod using .250" wall DOM tubing with BIG heim joints thru my brothers shop http://www.4x4labs.com/
he already makes tie rods and new steering arms for Land Cruisers and Mini trucks that put the tie rod behind the axle.
If anyone is interested in the possibility of mass production of these let me know.
Hope to have the first one read to test within a few weeks.

K