Disco 1 V8 Vibrations

[disco_al]

I suspect already what this could be, but here goes anyway.

I have already had a scan through the search results for vibrations in the Disco forum, and the general concensus for the symptoms i have is the prop u/j's. Anyhoo, this evening i started to get a strange vibration through the steering, around 20-30mph, while applying gentle throttle, for example while going round a roundabout. When letting off power, there is what can be best described as a "grinding rumble" from the front end area (difficult to say exactly due to the other rattles and squeeks). If i declutch, and drop into neutral, the same noise can be heard.

The only work done recently was the transfer box front output seal last weekend, and whilst it was apart i made a point of checking for play in the output bearing, and none was evident. We parked up in Asda (shopping day ) and i crawled underneath to have a check. With the handbrake off (wheels chocked for safety with my socket set) and the box in neutral, i cannot detect any play in any of the joints, there is no detectable movement in the transfer bearing, and everything else appears in order, although i will get it up on stands in the morning for a better check.

Am i right in suspecting dry u/j's as the problem? I suspect that removing the transfer end of the prop and swinging it out of the way mave have disturbed something, although i am a bit confused as to why it would show up a week later.

BTW, it's a 1990 Disco 1 3.5 V8 Manual

All suggestions are gratefully received.

Thanks

Al