Originally Posted by corwin1968

It's very possible that I am over tightening the preload nut, which I've read reduces the life expectancy of the BB. I generally tighten it until there is no side-to-side play in the cranks. If it still feels really loose (like might easily unscrew and fall out) then I just slightly tighten it a little more. Usually, the point where the play is gone is close to as tight as I can get it with the little plastic tool.

I also found at least one online thread where numerous people had Deore BB's that lasted a ridiculously short period of time and then they installed an SLX or XT BB and it lasted a long time.

Also, I weigh 400 lbs so I put a lot of pressure on the bearings. I took one of them apart last night and I was shocked at how small the ball bearings were. I expected something closer to the outside diameter of the BB.