Hi guys. I just bought a Kitchen Aid DD washer Model KAWS750LQ0 manufactured in Dec 2002. I had my appliance guy look at it and he said it was the cleanest 10 yr old washer he had ever seen. The outer tub was clean as a pin. He looked at the coupler and it was about worn out so he replaced it. At the time, he just turned on the washer and made sure it would agitate and spin, which it did. Today after using it for an actual load, It makes this clunking sound only when agitating in rhythm back and forth just like the agitator is moving. It can be a bit louder with a heavier load. I know the motor, agitator dogs and coupler are find. Do you have any idea what the cause is? All I could discover online is it might be the gearcase. Its fine when spinning-- just a loud clunking when agitating.