Thanks Pete. I was very pleasantly surprised how nicely the table performs after scraping. Maybe one day I'll get round to correcting the wear on my mill knee, if I'm feeling brave. The nut that secures the wheel on shouldn't affect the preload on my spindle bearings. The preload is applied with a wave washer at the rear and a sort of piston arrangement presses on this washer and is adjusted with a bolt at the back. One of the earlier posts has a picture of the assembly. I replaced the bearings on mine as the rollers and centre parts were a tad rough.