I am a recently new owner of my first Jeep, a 92 YJ,4.0L,5 speed,2 1/2 rancho leaf spring lift w/ 1" shakle lift & 33x12.50. From the begining I noticed the gear shifter would be a little hard to get into gear once in awhile. This week I noticed the tranny popped out of 4th & 5th gear a couple of times. Then as I shifted into 3rd it grinded like the clutch wasn't engaged, but not every time. The grinding isn't happening in any other gears at this point. Any info on the possible trouble/solutions would be greatly appreciated.

Well unfortunately my friend it sounds like you are going to have to pull the tranny. My 90 yj was doing the same thing- the synchros went bad. You can usually ride it out for a while, but if you are unlucky like me, it will get stuck in gear and you will be stuck too! If you pull it yourself, look to spend about 500 bones on the rebuild, but remember to check that clutch and flywheel! No reason to have to tear it apart again down the road!