The mechanic spotted that, with the bike on the centre stand, when you put one hand on the top of the wheel, and one hand on the bottom - there's about 1.0mm - 1.5mm of lateral play in the wheel.

His theory is that one of the bearings is going. Could it be anything else?
He also said that swapping the bearings is a big-ish job, and that he'd rather I take it to a BMW specialist - and suggested Ray near Preston.
We got chatting, and he's not certain about the bearing - could be something else - he also explained that there's a few guys who specialise in BMW final drives, and that often its best to just replace the whole rear diff. His logic is that, a bike on 50,000 miles, hoping to do another 50,000 is likely to need it at some point... so why not swap the lump in a oner...
Anyone had anything similar? How much will a rear diff cost me (just as a one lump part?)
Also - can anyone recommend someone who does them? I'm thinking if I buy the part, re-conditioned, in the next month or so, I can then have it dropped in on the next payday. Who sells them though? I seem to remember someone on the forum was a final drive specialist?
Maybe having mine taken out, and sent off would be best?
Just interested in anyones experiences / thoughts please!

Phil
Bury
Lancs