Carrier bearings

I have a funny vibration noise coming from the Jeep. I have been trying to get rid of it and have done everything that I can think of to get rid of it. Anyway, a few other folks with XJ's said they have had the same problem and it was the carrier bearings. I guess they said the carrier bearings start to go bad and you get a vibration at high speeds that gets worse the faster you go, which are my exact symptoms. My questions are.

1. How can I check if the carrier bearings are going bad. When I pull the cover will the carrier be "loose"?

2. Does changing the bearings affect your gear setup? I mean can I do it myself at home without any negative affect on the Jeep?

if you pull the cover and the carrier is loose that is a good sign. If you replace the bearing your going to need a press of some sort. It will change the backlash on the ring gear so they will have to be set back up. My carrier bearing gave up the ghost last month, when the loud noise started I didn't have time to really think about it, bang and pop were all I heard and they thing took out the ring gear and pinion gear. So get it done before that happens.
If you haven't changed the gear ratio yet now might be the time to do it, since the carrier has to come out anyway. Juice

First you need to isolate the vibration.I have never heard of a carrier bearing causing vibes,maybe a pinion bearing.Is it in the front or the rear?Have you tried removing each driveshaft?Have you checked all the shaft angles?Have you checked the slip yoke splines?

Whatever the vibration is i think it is coming from the axle. It is a horrible vibration at 60+ mph. It is almost unnoticeable with the driveshaft out but I can still feel it. I checked:

1. pinion angle f/r
2. changed u-joints and centering joint in front shaft
3. had shafts balanced

With the driveshaft off i can't feel any play in the pinion output.