To me, it's a bit strange that they have to make them with so much clearance
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The tube will rotate freely even if it was made tighter, don't you think....
Worst slop contributor is sideways - the tube ridge has a lot of extra space where it's locked in the housing.
Again, I can't see a reason for that much space.
BK: you're probably right about the grease, I'll use oil after cleaning the whole thing.