The shock should have come with the special conical shaped washers that when tightened down expand the grommet and prevent the shock from moving. I am assuming you have a YJ not a CJ. Oh and welcome to the forum
This shock is the end that comes to a "T" and attaches with two bolts. The rubber grommet has a center piece that would represent the top of the T. Do they come with washers for that end? I have a 1998 TJ.