the rear end in my ZJ is loud. very loud.  it sounds like the whine of a bearing.  i've never changed a rear wheel bearing before. i believe its a non cclip axle but i have to pull it to check.  i haven't checked much out yet, just wondering what kind of job it is, tools, tips etc.  also, how do i tell the difference between carrier bearing wear, pinion bearing wear and wheel bearing wear?  if its a rear wheelbearing i'll fix it. if its a carrier bearing i'll junk the axle. no problems there. 
cheers.