Sorry for the wrong title - I did some additional test and apparently my original thought is wrong...

The model # is WNSE4200A0WW. I took off the cabinet and it is a belt-drive model. The belt feels fine. The motor is running and the belt is working, then within a minute, there are loud noise like something block the rotation and I had to stop it. (this happens both in washing mode - after filling in water, and spin mode) I just test it seems the agitator did rotate. It is not always failing - sometimes both washing and spin are fine without any noise, then sometimes suddenly both will not work from start or after a short period and will produce noise. Draining is fine. Please give me some advice, thanks!

Check the pulleys. Are they spinning freely with the belt off? Does the transmission turn freely in both directions? Also could be the basket drive assembly Clutch and brake. Check these for wear. Also could be the centerpost (spin tube)bearing