I found this link on the net that has to do with driveline noise. And I read a whole bunch of other forums that all came to this conclusion and/or exssesive blows to the T-case itself from previous owners abuse. Hope it helps.

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml


2002 4dr Kia Sportage 4X4
Tires:235/75/15, Wheels: Black 15x8 Steel ProComp 2.5" B.S., Hubs:Warn Manual, Lift:3" UPYOURKIA, Trailer Hitch, Cargo Rack, Clinometer.