SpacedOutXj

Yet another horrible attempt of describing a noise over the internet. I'm running a 3" rustys lift with 31x10.5 with 4" back spacing...all on a 96 xj sport (185k). I just replaced the front bearings. Long story short, I thought I heard the fronts about to go so I replaced em and they kinda needed it, but I could have survived with out and the front noise still persists. Now for a while in the rear, everytime I drive around with the a/c on (windows down haha) and I drive by say a tree or guard rail, I can hear an echo from the back that kidna sounds like bearings, but I cant really tell. Is there I way to check the rear bearings with out taking too much apart? or am I hearing a different problem? Also not even really sure it is a bearing noise I hear cause there is no pitch change while driving