I used to have an old mini that failed an mot on all 4 UJ's, every time you put it in gear in clunked, had done it for years but no mot picked it up until i moved house and changed garage. took them apart and on some of them there was the inner cross piece's, the outer buckets but no roller bearings, you could grab the drive shafts and turn then quite a way, been driving like it for at least 3 years, the clunking was the slack being taken up :) in past experience i would say you should be fine but thats only my choice, up to you really. if dont put full power through i would guess you should be ok, but up to you really. rich