I know this is long-dead, but for future readers of the thread, save yourself a lot of time and effort and buy a new rear-half drum from Seme-Nedis, who supply the trade.
Their retail site is http://www.allourparts.com/
C00119357 :- Rear 1/2 Drum with Bearings, at £55
and buy a new spider - 'cos if it's been making the noise for a while, the shaft is probably corroded
C00117329 :- Spider at £31.75
Should only take a couple of hours with those two, and last for ages, as the bearing has been factory fitted!
numpty
May 2010