Outer Limits 4x4 Board

I have had a vibration on the drivetrain in the lux lately (95 diesel).
Replace a couple of bearings in the transfercase about xmas and put new unis on the tailshaft (rear) about 1 month ago. .
Still a slight vibration, but has got worse around 80kms then disappears.
Going to work last week the car seemed to be locking slightly stopping at traffic lights etc and, well, something didnt sound right.
When I turned into my carspace at work something went bang.
I thought it was the diff, so before i left that night, took out the rear tailshaft, locked the hubs in, into high range and drove it home. No noise, no problems, no worries.
I toko out the diff the weekedn, but before I did, I rehecked the tailshaft. There was no slackness or slop when i wiggled it at the diff end.
The crown wheel seems fine, no missing teeth or anything, there is no noise when I spin it at all.
The rear bearings on the axels were replace early last year and there is no nosie out of them at all either....
Any clues guys!

Sounds like it could be the center bearing on the tail shaft

I had it converted to one piece a couple of years ago

sorry, not giving any input into the situation but mine also does the same thing but I've still got the centre bearing. I replaced it a couple of weeks ago and only went on the freeway for the first time the other day as soon as i Hit 100 it vibrates like crazy but goes away about 115+ anything under 100 and it's fine. What would be causing it?
I'm pretty sure I installed the centrebearing correctly although I did do it myself for the first time so maby i've done something wrong hey??

Your front hubs arnt in or anything?

nope

did u mark the tailshaft before slitting it?
if not u may have put the shaft out of balance

nah marked it, although maby I didn't tighten it enough>?

I just had a problem like this. Found out to be the main bearing at the input to the gearbox was lose in the housing. I think this waz the problem but haven't put the box back in yet. will do it soon tho. Got a mates box in there at the moment and its fine.

Would this still be the problem if the rear tailshaft was disconnected as in my case?

I did the same. I disconnected the rear tailshaft and drove on the front. No worries. I think that the force driving the front shaft takes away the vibration. Connect the rear shaft and drive on it, the vibration gets increased down the line.
Put my box back in yesterday with a new main bearing ($45) and a secondhand front box housing ($80). Make sure that you loctite the bearing in the housing when you reasemble.
Works fine now.
When you pull the box apart remember to remove the reverse sender. you will need a bearing puller for the front bearing. (you mightn't have to replace the bearing, But to be safe I did). Put the bearing in your oven to about 170'c. This will make it eaiser to get on the shaft but be quick to hit it down. OR JUST TAKE IT TO A GEARBOX REPAIRER.