At the MOT of my 4x4 sapphire the tester was saying there was play in the front left wheel bearing. When I was going to replace it I found out the hub retaining nut was loose. I tightened it back to what it should be and there didn't seem to be any play more. I find it strange that the nut was loose, it probably was already loose when I bought the car half a year ago. Does this happen more often? At the left rear wheel the hub nut turns the other way to prevent it from coming loose and the nut is a nylon locking nut. But the left front one is just regular thread and has no nylon locking nut. To me it seems like it can be loose again next week, or not?