probably not doing anything wrong, this kind of stuff always happened when i had shimano. i bought cartridge bearing hubs.

I've had rears loosen in the distant past. Now, my routine even with brand new hobs is to Loctite the very snugly done up [b]drive side[/b] cone & locknut at the correct position on the axle. I do this with both and rear hubs, so adjustment is then always made on the non-drive side/disc side of the hub only. I never have problems getting correct pre-load (minor free play with QR loose, which goes away when QR locked).

Hope that helps.

Had a problem like this with an XT hub last year - no matter what I did as soon as I put it back on the bike and started to use it, it would "self-adjust".

I finally figured out that it was the Freehub that had come a bit loose (small movements back and forth on it's thread leading to "fine tuning" of the bearing preload) was causing all my grief - school boy error I know, but worth checking if you haven't done so already.............

It was driving me bonkers before I discovered it!

Never needed to use loctite, can't see how tightening on the disc would matter either.

Just set it a bit looser next time?

aye, centrelock has nothing to do with the axle.

Thanks all.

I know the centrelock has nothing to do with the axle, but at the same time the bearing preload does change after I've done the lockring up.

I'm thinking I've somehow crimped the metal seal on the cone when I'm doing up the lockring so the metal seal binds on the hub, over time I guess this would cause it to loosen.