My 1991 Jeep Cherokee is making odd sounds. First off, while Im driving, if I hit a bump or something there is this little squeak. It's not anything motor related, and it sounds like it's coming from the right side front/rear door area. Also, my engine makes this slight tap tap tap tap as it runs..is this normal? Lastly, when I shift into drive (automatic) theres this noticable bump, however when I switch into reverse, this is the rather load bump and the rearend seems to drop a bit. Another thing, when I go on interstate, i vibrate a little bit. Is this normal since its a 4wd and has those bigger tires on it? Thanks for help!