I have a one year old GE top load washing machine WBB4500G0WW and the tub nut keeps coming loose during the spin cycle making the freight train noise. No matter how I tighten the nut, it comes loose again after each load. I tried replacing with a new nut, but no luck. Can a transmission/bearing problem be the reason why the tub nut keeps coming loose? I took apart the washer today and didn't notice any leaks. The tub cover has cracked though. Thanks for any advice you can give me!