I have a 2000 D2 that has 98K miles on it. When completely stopped and shifting between R and D (or D to R) there is an audible noise somewhere between a "clunk" and a "clack" that sounds like it's coming from either the transfer case or transmission. Both of the driveshafts appear solid. I checked them both when I lubed them a couple of months ago, and all U-joints appear to be good. I looked underneath while my wife cycled from R to D and back again a few times. It looks like both driveshafts spin a little until they take up the freeplay in the diffs/axles and that's when I hear the noise. When she put on the parking brake it did the same thing, only the noise was quieter, and of course the rear driveshaft didn't spin. This is something that has become consistent in the last few weeks or so.
Thanks in advance for your help.

 

It is normal, my '97 does the same thing. There is slack in the gears, both in the t-case and the diff's. You can help quiet this by having the fluid changed in both the diff's and t-case, have a 95w140 weight gear lube put in. If you use a full synthetic gear lube it will slow down the wear on the gears.