I used castrol LM grease on mine.
Also, when I took the wheel out to change the fork seals, my speedo drive was broken in two.
After the tears had stopped clouding my vision I checked what eBay had to offer. Passed out at the cost and decided repair was the only option.
Degreased, lightly sanded and araldited it, greased it and put it back together.
I think the fact that the break looked like a serrated edge means it's got enough lateral interference to not put too much strain on the bond.
So broken speedo jobby doesn't have to mean end of the world!