I am thinking that something is wrong with the brakes, which keep the tub from spinning during the agitation cycle. Given the difficulty of this repair I would say live with it until it either fixes itself (unlikely) or you cannot stand the noise (more likely) or it fails, in which case I would replace it with a new one. Basic top loaders are being heavily discounted in our area, so for not much more money than the cost of a repair you can have a nice new machine.