It's your bumpstop. Have one fabbed up and welded in there. It's just a capped piece of tube. Measure the one on the other side, if its intact, for reference.
2002 WJ Overland - 4.7HO - 231tc - 6" Clayton - 285/75-16 Cooper STT - ProComp 5129 wheels - Kevin's Offroad Belly Skid and Rock Sliders - JKS Track Bar and Disconnects - ProtoFab bumpers